Honest question, why are you trying to include lore from other media (books, even other games) into BG3s timeline?
It's a rule known to all D&D players: Every DM creates their own world. They might use a known setting, they might use characters or other elements from a setting, but at the end of the day they decide how the multiverse works, what Gods are / are allowed to do / how they work. How magic works (if it even exists) and the timeline are 100% up to the creator.
That said, there are definitely things to discuss about BG3s timeline in particular, but anything from any other sources (including BG1 and 2) should be ignored imo. They included elements from BG1 and 2 but in LARIANS world they can act however Larian decides and whenever Larian decides. Bhaal has become active when Larian says so, etc.
In short, the only lore that matters for BG3 is BG3 lore. Just like you don't go on about how Elminster SHOULD BE according to x source when sitting at a DMs table.
The thing is, this isn't just a random game at a table. This is an officially licensed game that unless I'm mistaken, is actually now Canon to the timeline of the forgotten Realms. They are adding to the timeline that will be considered Canon going forward, so expecting it to fit with Canon already established is entirely reasonable. Even if that weren't the case, how can you suggest anything from the precious two games should be ignored? This is a direct, numbered sequel to those games, so while reveals and retcons are certainly acceptable, saying they should or can be ignored is not how sequels work. That would be like if the second Indianna Jones movie started and he was a British museum director and not an American teacher.
