When I try to determine what the right date is for a recording, if they exist I look to sessionographies either in the physical media or online. One that I go to a lot:
This information for a bunch of artists is scattered across the Web in specialist sites by devoted fans, sometimes by the artists themselves, and can often be hard to find. It’s not difficult to look up a recording in Musicbrainz, but there’s no view to see a complete (known) sessionography that I’m aware of, maybe limited to just recordings with a date for instance. It would be a great resource if there were a way to make this available in Musicbrainz - and might also make it easier to identify recordings that ought to be merged, for example.
Pretty sure this has been mentioned elsewhere, but until there’s a massive overhaul of MB’s data structure (ie., not likely to happen soon), annotations are a great place to store information like this. (And while they may not be readily machine readable, they should at least be human readable, so serving the purpose of helping humans decide on whether to merge recordings etc. or not.)