Poor Eddie Van Halen...in pop culture, he's probably best remembered for a guitar solo on a largely synth-driven pop song where he's essentially playing a bit part while being overshadowed by a charismatic performer who he hated, but who nonetheless danced up a storm onstage, who had a voice that's just perfect for the music, and some annoying vocal tics. I am of course referring to the singer David Lee Roth and the song 'Jump'. Did you think I was referring to 'Beat It?'

The American metal community in 1982, when Thriller was released, was still in what was very much a formative stage. Metal was popular in concert halls, but struggled to get proper mainstream success in terms of radio airplay and coverage in prominent music magazines like Rolling Stone; it was 1983-1984 when metal exploded (see 'Jump').

In the book Sound Of The Beast: The Complete Headbanging History of Heavy Metal, Ian Christe points out, in 1980-1981, that:

...for Americans who witnessed AC/DC live, or saw photos or a rare video of Motorhead or Saxon performing in Europe in front of thousands of fans, the good times of Van Halen could not compare.

This does suggest that Van Halen were always seen as a bit shallow compared to 'proper' metal by dedicated American fans. However, those Americans had not yet found each other, and Christe gives an example:

Ron Quintana wrote a letter to [British metal magazine] Kerrang! requesting pen pals. "I wanted to network with other Americans who were into heavy metal," he says, "rather than Ted Nugent or even just the same generic Lynyrd Skynyrd hard rock that everyone was into. writing to an English paper was the only way to get in touch with other hip Americans to trade heavy demos and bootlegs. They printed my letter in Kerrang! No. 4. That summer I started averaging ten to twenty letters a day, so every day would be just like Christmas. I'd get amazing packages with amazing bands that nobody had ever heard of...six months after his distress signal appeared in Kerrang!, Quintana...[had Metal Mania,] a full-fledged fanzine, complete with live reports and editorial essays.

In other words, at this point, the counterculture of metal in America was still very much embryonic. And when metal did explode in 1983-1984 it was thanks to teen magazines like Circus and Hit Parader, and MTV - it was pop. It was only during/after this period that metal bands started to prominently draw a line between themselves and pop, as you get thrash metal bands like Metallica and Slayer who very clearly defined themselves in opposition to the MTV stuff (Metallica rather pointedly not releasing videos during the height of the MTV era, for example).

And Van Halen themselves dismissed the idea that they were heavy metal in 1984 (according to Eddie Van Halen in a 1984 Guitar World interview):

What is rock and roll? It’s a feeling put out at a high volume. To me, heavy metal is just rock and roll. I guess the more leather and studs you wear, the more heavy metal it is. So I wear funny striped clothes. Sometimes the way you see yourself is not the way others do. I sure as hell don’t see us as heavy metal.

Elsewhere, people seemed to see Van Halen as simply a paragon of 'American hard rock' (to quote a profile of the band in the UK magazine The Face from 1984):

Hard rock doesn't get any bigger than Van Halen, whose six albums in a ten year career have all gone platinum. Their guitarist and namesake, Eddie Van Halen, was the soloist on Michael Jackson's 'Beat It', lending the group a grudging respect in some circles. For most of us, though, they remain beyond the pale, which is just how we like them.

Rock magazines were, it must be said, a bit sniffy about Van Halen, as The Face alludes. Rolling Stone's review of Van Halen II drips with snark:

Dig it or not, I've had this amazing thirty-one-minute artifact on my turntable for hours, and after almost one careful listening, I'm utterly convinced that the members of Van Halen must have been up half the night creating it. What an effort.

For Van Halen's 1984 record, Rolling Stone are less snarky, but instead focus on their pop smarts:

This album confirms what a lot of Van Halen fans have suspected for some time: this is no mere arena-rock band. Beneath all the strutting and heavy-metal antics lies a band with more pop savvy than a dozen Journeys, as well as the chops to pull hooks from the most unlikely places.

Note that the 1984 review is implicitly denigrating 'arena-rock' and 'strutting and heavy-metal antics' as being beneath their readers.

To put Michael Jackson's Thriller in context - as is suggested by the quote above - it absolutely was a completely unashamed cross-over pop record - Michael Jackson was trying his damnedest to cross over to a white audience, and so the album is full of white people from other genres. Thus Eddie Van Halen on 'Beat It', but also 'The Girl Is Mine' with Paul McCartney, Vincent Price on 'Thriller', and Toto as the backing band on 'Human Nature'. Contemporary reviews of Thriller where they mention Eddie Van Halen at all, mention him in this context:

You get some funny ideas when you have to follow-up the likes of Off The Wall – the ones put into action here reek of desperation, falling back on old showbiz lags like Vincent Price and Eddie Van Halen to cover the lack of inspiration in the music (Gavin Martin, NME, Dec 82)

Good old Eddie Van Halen, that showbiz lag! This was a common theme in initial reviews of Thriller, though not everyone was so negative as Martin:

[Michael Jackson's music] is at least as much cultural artifact as pure art. So it's certainly no accident that Thriller features guest spots by Eddie Van Halen, Paul McCartney and Vincent Price, such disparate sensibilities yet all exemplars of pop mythologies sacred and profane, and each self-deprecating enough to never take any of that too seriously (Mark Rowland, Musician, Feb 83).

In terms of rock critics and how they felt about the collaboration, Barney Hoskyns' profile of Michael Jackson in the NME in 1983 mentions that 'anything that brings Eddie Van Halen and 'Soul Makossa' under one roof is in my book pretty cool.' Hoskyns here was approving of Michael Jackson's desire to take bits and pieces of different genres and merge them.

The Rolling Stone review by Christopher Connolly in January 1983 discusses how:

Maybe the best song here is "Beat It," a this-ain't-no-disco AOR track if ever I heard one. Jackson's voice soars all over the melody, Eddie Van Halen checks in with a blistering guitar solo, you could build a convention center on the backbeat, and the result is one nifty dance song.

The Michael Jackson solo doesn't seem to have hurt Eddie Van Halen's reputation very much, in any case. In the previously-quoted 1984 interview with Steven Rosen of Guitar World, Rosen says of Eddie that:

Like any true artist, he never plans or conceives. He just does. Whether this record sounds like the last one is of little concern to him. What he does do is ‘try" and while he (self-admittedly) does not always succeed, there is an underlying quality and integrity in every note he plays.

Which is probably not would be said of him if metal guys thought he had broken a sacred trust by playing on a pop record. I'd probably have to dig further into difficult-to-find metal fanzines to see what the embryonic American metal community thought of Van Halen during this era, but the vibe I get is probably that they'd get faint praise - they had a bit of cred because Eddie Van Halen was an influential guitarist. But overall, Van Halen were too pop to be the real deal in the first place, compared to the proper New Wave Of British Heavy Metal stuff that they preferred.