I can see one major issue with bringing back party members from the first two games. To even figure out who could come back, you would have to spend the first 30 minutes of the game laying out what choices you made in the other two games. Did Revan fall again? If so, there goes Carth, Mission, and maybe Zaalbar. Did Revan kill Bastila on the Star Forge? Maybe Revan redeemed himself, but couldn't bring Bastila back to the light.
TSL had many more choices about killing off characters. Honestly, if KotOR 3 is ever released, it is going to need an entirely new party. I'm not going to want to waste a bunch of times going over which endings I chose in the other two games.
Just my opinion though, some people may like this minute level of customization. I for one abhor busy work.