WoTC's current policy in regards to canon is absolute trash. Every table has it's own unique canon. Hell, even Ed Greenwood's home games are pretty divergent from 'official' realms from what I have heard. It was never as if WoTC was going to send the Pinkertons to your home if the Spellplague never existed in your personal campaign or whatever. Certainly WoTC stated intention to not give a damn if their modern releases are even remotely compatible with stuff from prior editions enables any particular 'freedom' at home games. If anything it makes any sort of consistency at home games that much more challenging since you and your players could come to the table with drastically different expectations on the setting and lore depending on when they started playing and what material they are familiar with.
I mean heck, imagine a hypothetical Haer'Dalis cameo in BG III. What would he look like? I can imagine people being dissapointed/confused/surprised no matter what direction Larian took it, since 2e Teiflings were completely different than the ones we see in 5e and in BG III currently.
BG III is currently in a weird place because of a multitude of discrepancies like that. It's impossible for BG III to be faithful to BG I & II and also be faithful to 5e, which whatever WoTC purports, is important to them.
As for Minsc and Jaheria, lets be honest, particularly in regards to the former, their presence in the game is somewhat of a stretch.
