From the datamined content we know that the three remaining PHB races (Half-Orcs, Gnomes, and Dragonborn) are very likely to be added since there's already quite a bit of existing content that uses their tags.
IIRC there's also some evidence of some uncommon races being considered such as Warforged, Duergar, Kenku, Tabaxi, and Genasi since people have found tags and lines for them. I wouldn't put too much hope on most of these uncommon races ending up into 1.0 version of the game though since it'd be difficult to create so much content reacting to so many different races.
We SHOULD(?its been 2 years EA + probably over 2 years of internal dev….?) get the other main races but for the rest…
Dream on. Never ever will Larian do that. Because for them, LESS of EVERYTHING is more apparently.
Less companions
Less classes
Less Races
Less immersion (day/night/time)
Less encounters
Less NPCs
Less spells/abilities
Black Isle would be proud! (sarcasm)
BG1/2 have 7 races in total: Human, Elf, Half-elf, Dwarf, Halfling, Gnome, Half-Orc.
BG3 currently has 8: Human, Elf, Half-elf, Dwarf, Halfling, Gith, Drow, Tiefling. There's atleast 3 more common races from the PHB that are likely to be added after the EA. That puts the number of races in BG3 well above the number of races in BG1/2.
BG3 will also end up with all 12 PHB 5e classes: Wizard, Fighter, Paladin, Ranger, Druid, Monk, Barbarian, Bard, Cleric, Rogue, Warlock, and Sorcerer. This is equivalent to the number of classes in the EE versions of BG1/2 (Fighter, Ranger, Druid, Paladin, Barbarian, Cleric, Monk, Shaman, Mage, Sorcerer, Thief, Bard) and 1 more than the base non-EE versions of the game.