There's no real guideline for this, really. There are subjects where The Consensus is still based on interpretations from 40 years ago, there's others where there's still no consensus at all or where the consensus is changing with every new publication. You could argue that there has to be a cut-off point where the theoretical underpinnings become too outdated, but we really shouldn't kid ourselves about historians' relationship with historical theory - many aren't all that interested in that side of historiography and most will at best follow the trends within their own field, which will inevitably lag behind. And even if you've got a particularly theoretically diligent historian, there's still not a single Correct type of historiography (and there never will be). So you can still have four different and theoretically up to date historians present four different interpretations - none of which are outdated and all of which deserve attention.

Best you can do is look/ask around, read reviews, see which works are hot in the field right now. I guess newer works will be more interesting by virtue of having the most other works and theories/trends to take into consideration, but it's not a given. I guess my answer is me shrugging my shoulders somewhat apologetically.