Look, you're not wrong but WoTC made every possible terrible decision in establishing that canon adventure.
Well, Larian's hands are tied when it comes to some characters.
Their character and fate after ToB have already been determined, so they can't invent a new past.
It would be incredibly cool to meet still grieving Archduchess Viconia in BG3 and help her "move on".
After all, the players have training when they helped "move on" Jaheira
