It really depends on the technical necessities of the tasks related to said persornal quest, and wether another character can do something in their stead. Let's say you need to cast a specific spell to complete a quest, maybe the game will juste give you a scroll for it, or maybe any spellcaster can do it. It's a roleplaying game, there are options.
And it's fine with me if it makes some personal quests harder in some way. It would be a reasonable sacrifice to make, I think, so your party can include both the personnalities and the classes you want to have around. Especially if it's, let's say, your fourth or fifth playthrough.
But yeah, we'll be sure soon enough and if classes are set in stone it's not exactly an issue or a problem.
No, that isn't the problem at all. The issue is how will the stories be written? Gale's and Wyll's stories and their classes seem to me to be inextricably linked.
Astarion's former vampire master shows up in his personal quest, as we have already seen. Since she is featured in the character art at the top of this website, it is pretty safe to presume Wyll's warlock patron will appear in similar fashion. Their entire relationship is premised on her giving him the powers to become a frontier folk hero in exchange for his soul. If he isn't a warlock, how do they write around that? Wouldn't the writing of the entire questline have to be very general, always avoiding specific details? That doesn't sound compelling.
Gale is a prodigy wizard who tampered with Netherese magics beyond his control and has become living weapon of mass destruction. If he is a fighter then this doesn't make a lot of sense.
I suppose Shadowheart could be written in an ambiguous way where she could either be a cleric or a cultist of Shar, but even then, it seems to me that trying to write an entire game's worth of dialogue and always avoiding specifics might come off as stilted. What if you make her a druid? Are there druids who worship Shar?
We will see, though.
