Nekoo
Smash Master
This. This. And this Again.Multiple people can point out that K. Rool was not at all popular during Brawl speculation. No, that belongs to Diddy Kong in terms of DK characters, Rdiely overall. K. Rool wasn't even a blip on the radar then.
If we are to go by the logic that you're suggesting then Isaac is a ****ing shoo in but alas he's looking less likely for base as the days go by.
The Brawl Era Speculation feels like it's getting a constant revisionism.
Ridley was THE most wanted.
Then Sonic but he got announced and broke the internet in half and got into news, because Jesus MARIO VS SONIC FOR REAL.
Diddy was also asked a ****tons with Dixie.
After Sonic, Megaman was asked a tons
And Cloud was in everyone's Top 10 wishlist of Characters they wanted in. Even if impossible back then.
And that's it. There Characters that had a growing fanbase but characters like K.Rool and Geno only got a second life for Smash 4 (K.rool) or DLC/post DLC (Geno)
The only Characters I think is "worthy" of being Ridley/K.rool follow-up is Isaac.