My most wanted characters for this game were:
Ridley - Big Metroid fan and have beaten all of the main series except the original GB Return of Samus
Simon Belmont - Had Simon's Quest on NES and love the Metroidvania-style games (Symphony of the Night and the GBA/DS games)
K Rool - beat DKC1 & 2, DK64 (and DKC Returns and Tropical Freeze)
Still would like Dixie Kong.
I main Mega Man in Smash 4, and I owned Mega Man 1-6 on NES, and have beaten all of the main series, Mega Man X 1-3, Legends, etc. However, I also main WFT and I've never "played" Wii Fit.
In the context of Castlevania itself, I don't really care about Simon Belmont very much because I'm a bigger fan of the metroidvanias, but he would represent the franchise as a whole better then Alucard. Also, there's a pretty good chance of Richter being an alternate costume, since Simon will likely have to steal some moves from him anyway.
I agree, in that while SotN is my favorite Castlevania, Simon and the Vampire Killer whip are far more iconic and representative of Castlevania than Alucard is.
However, Castlevania 2: Simon's Quest definitely has Metroidvania elements, like non-linear gameplay, weapon upgrades, leveling up, collecting subweapons, etc. But the gameplay doesn't hold up as well as SotN and beyond, so I have more nostalgia for the game than desire to replay it compared to later games. It would probably be a good candidate for a remake with some modern elements like, you know, a ****ing map.