Realistically, there is only so many 3D characters are worth salvaging - that is those with either a good storyline and/or design. The reason Tanya. Frost, Quan, Kenshi, Bo Rai Cho etc returned was for exactly this reason. Characters in these categoried are immediately salvageable and are certainly the ones I would be focussing on first. I think that needs to be how EB etc look at it. For me:
Good Design and Storyline
Li Mei (won MKDA and then possessed), Shujinko (protagonist of a game with good design), Ashrah (different design and cleansing storyline interesting), Havik (interesting chaos concept between good and bad)
Good Design
Nitara, Hotaru, Sareena
Good storyline
Reiko (interesting ending), Taven + Dagon (TERRIBLE Generic design, and I would like them to never return but were the pro/antagonist of a game),
Neither
Jarek (generic lackey), Kai (generic good lackey), Mavado (generic lackey), Hsu Hao (generic lacky), Drahmin (generic Lackey), Dairou (Generic Lackey), Darrius (generic Lackey), Kobra (Generic Lackey), Kira (generic Lackey), Meat (joke character).
The reason we have not had Stryker apart from MK9 / MKA was because he too fell in the latter category.