I was reading Ulinka Rublack's A Concise Companion to History, which in my amateur judgement I found a really interesting and stimulating snapshot of the discipline. In the "Commerce" chapter Kenneth Pomeranz briefly mentions FoxConn, and in the footnote writes "Basic facts about FoxConn are available at https://en.wikipedia.org/wiki/Foxconn, accessed 2 Feb. 2009," although he does go on to point towards a 2007 dissertation for "a more scholarly account." Even more strikingly, in the "Gender" chapter, Dorothy Ko writes "Although writers since the fourteenth century have used gender to refer to femininity and masculinity as types, its primary usage had been confined to grammatical distinctions," and the footnote in its entirety just reads "https://en.wikipedia.org/wiki/Gender."
There are hundreds of footnotes in the book total, and as far as I can tell all the rest point to standard academic resources. Has citational practice in history or other academic fields become increasingly accepting of Wikipedia, or is this just an unusual outlier? The nature of the book as a "Companion" is more to give a survey of a certain research topic like "Commerce" or "Gender," so is this something you can "get away with" if you're writing at a more introductory level?
Now I don't know anything about "Foxconn", but I do know quite a bit about medieval gender. I also don't currently have access to the book so I'm going to take your word for it that these are actually the citations.
There are a few books on the subject of medieval gender and a ton of academic articles, and if the author and editors wanted to find a decent source for that information (if what the book says in your quote was actually true, which I don't think it is) it would not have been hard to find. That's shoddy on the part of both the historians and the publisher. Also, you are very observant! I've looked through academic reviews of that book and many of them make no mention at all of the use of Wikipedia as a source, so they must've missed it. Most of them say that the book is surprisingly good for a book of its style, but that for a "global" history it has a big problem in that it's written entirely by historians from the US and Europe - 5 of them are just from Cambridge - and this means a lot of the historians are not really in their area of speciality when they start having to write about medieval south-east Asia, for example.
While Wikipedia is ok for checking basic facts such as what year a king died, the more complicated the topic the worse it gets and I would never cite Wikipedia as a source in anything because there will always be a better version of that information in an academic book or article (usually the stuff the Wikipedia article is based on!). We don't even allow it to be used for posts on our little subreddit, for reasons we first laid out nearly a decade ago..
Furthermore, if a historian has taken leave of their professional senses and cited Wikipedia, they should at least make an archive of the web page and note the date they last accessed that page. Wikipedia pages are ephemeral; they change, and can change quickly and drastically. The page cited will not exist as it does today in perhaps as little as a few weeks, and it certainly won't in a few years. Printed books do not change once they are physically off the presses and on their way to the customer. That alone makes citing Wikipedia without an access date for the page unacceptable. There is a proper way to cite websites that should be used, which apparently has not been used. Why Oxford University Press saw those citations and went "yeah they're fine", I don't know. If a student did that they would haemorrhage marks. There is now absolutely nothing to stop me going to those Wikipedia pages and changing them so they no longer say what these historians think they do, and they would have no recourse. There is nothing to stop me going there and "updating" the article with misleading information, such as changing the historiography to be a load of disingenuous quackery.
For example, see this thread from just 15 days ago where someone asked about the Wikipedia page for biological warfare in the Korean War and the response from /u/Georgy_K_Zhukov begins with "The Wikipedia article is awful". Search "Wikipedia" on our subreddit and you'll find loads of posts like that.
Wikipedia sucks.