Geromino: Sigh.
Why yes BG2 introduced Barbarian, Monk, and Sorcerer. Also most kits, except the ones the EEs introduced, and the new mage specialization Wild Mage.
The EEs introduced Shaman as well as Dwarven Defender, Blackguard, Shadowdancer, Dragon Disciple and the two Monk kits
Btw to this day nobody has implemented Ranger/Druid, Druid/Mage and Fighter/Druid/Mage, all of which are *official* AD&D multiclasses of the 1995 AD&D PHB. Apparently they used the 1989 PHB which didnt have these multiclasses yet. So they got omitted in the original game and nobody has corrected this ever since.
And yes strangely enough Ranger/Druid was a thing in AD&D, despite the obvious conflict of alignment requirements. Apparently in the 1995 AD&D PHB the Druids have been expected to be NEUTRAL, not TRUE NEUTRAL, just like Bards, thus R/D has to be neutral good.
If they ever make another iteration of BG 1+2, I would also expect Warlock and Favored Soul.
I think at least some of those multi-class combos may be implemented in the Dark Sun CRPGs (at least the first two; there's no way to play Crimson Sands these days).
Then again, that setting has some major differences in races and classes. For example, you have Preservers instead of Mages (and Defilers appear as enemies). Druids also are the only class to get spells like Cure Serious Wounds; Clerics get only spells of their element past the 3rd spell level.
The one old class I'd like to see implemented is the 1e Bard, which can only be accessed through some fancy dual-classing that would probably be more feasible in a CRPG setting than in tabletop. Chances are very few people have ever had a chance to play this iteration of Bard. (Bard is a really strange class in AD&D; the 2e Bard, in particular, has never felt like a Bard to me.)
(By the way, I believe Wild Mage appeared early during 2e's lifespan, in 2e's Tome of Magic, along with some Cleric spheres containing some very unusual spells. There's the Numbers sphere, for example, which would be perfect for a cult similar to the Pythagoreans.)