Unfortunately, barring magical mishaps like Minsc got, most everyone who isn't of a long-lived species like an elf or dwarf from the old games is dead of old age- if one of the multitude of disasters plaguing the realms in the intervening century+ didn't do them in first. That goes equally for characters from *all* the other D&D games as well, since MMO excluded, all of them are pre-timeskip. (3rd or 2nd edition) I'm not holding my breath to see a Deekin Spellsinger or Allessia Faithhammer cameo any more than Keldorn Firecam-their fates are pretty much sealed by the passage of time.

If we are lucky we might meet one of their descendants, find a magic item attributed to them, retrace the steps of their exploits, or hear of their past deeds from npcs. That would be neat.