I am generally fine with more 3D era characters returning because some of them could be great. I thought there were some good concepts for characters in the 3D games that just weren't fully realized, but could be pretty bad ass with the modern rework. Personally, I would like to see the roster be about 1/3 classic characters/ 1/3 3D era, 1/3 all new.
Personally, I would also accept no classic characters, some 3D era ones, and 80% of the roster being completely new. I just think for the series to meaningfully move forward you have to leave the past behind at some point. I also understand that I am in a small minority on this.