I understand you want the new game to have strong ties to a game and a story you like, but to be fair games where you are playing the same main character and takes place at roughly the same time of past games and somewhat continues the same story are a rarity. There are few great exceptions, like Mass effect, Gothic, the witcher or POE games.
In most subsequent installments of the same franchise the game advances in time, in place, 95% of the games have a different MC; takes place in another world, or the new game tells the story of other people in the same events that takes place in the other games (Like in valkyria chronicles, where you play different squads fighting in the same war) But the usual is that the new game takes place many years before with different characters and setting, like in KOTOR and KOTOR2, in the same world but in different locations without much ties to the original story, like in fallout, fo3, fNV or FO4; in other city and other time with different characters, like GTA games; In other galaxy like Mass Effect-Mass effect Andromeda; in the same world but in other place many years later like TES games; in a new setting like FFgames; 50 years before the previous game like in drakensang and drakensang TROT; In different kingdoms of the world at a later time with distinct factions at war, like Suikoden and Fire Emblem games; same place but years later with different story and enemies like NWN or IWD franchises; in a complete alternate reality like Fate games,...
Sometimes you met a few of the people you met in the past games or visit some common places, but they rarely have a huge impact in subsequent installments of the same franchise. If the game takes place a century later, with the previous crisis already resolved, you can expect the world has changed. It´s the usual.
I understand BG is a legendary IP that deserves a great game, but I do not think its fair to impose unrealistic expectations about the new game.
