Can we pretend like Dragonspear didnt happen?
We can, but Baldur's Gate 3 won't. If we ignored it, we would have to acknowledge the fact that it would mean the final boss of the Icewind Dale game is still alive in Avernus and likely to return in a future D&D game, which he already did, Siege of Dragonspear tied up that loose end. Besides, Larian confirmed last year that there will be some lore details hinting the events of Siege of Dragonspear in Baldur's Gate 3.
