Now, I hope they'll add Jonathan Morris and Julius Belmont as new echo fighters of Simon and Richter, and maybe Shanoa as playable character...
Richter is already considered an echo fighter of Simon, unless I missed something big.
... Oh, and why not Nathan Graves and Reinhardt Schneider? I'M AB-SO-LU-TE-LY SERIOUS.
Probably because most casual Castlevania fans have forgotten who those guys are entirely, owing to the fact that their games weren't all that popular.
I mean, I get and appreciate that you're excited, but Smash is a celebration of
Nintendo, not
Castlevania. Several of Simon Belmont's games were staples of the early Nintendo library, warranting his inclusion. Richter is a very popular character, showing up as a primary character in
three nope, four games (initially forgot DXC, remake status be damned) and making cameo appearances in several others, so it makes sense that he'd also be included. These are characters with big, broad fandoms.
Johnny Morris Smol Bean Edition, Julius, Nathan Graves, Reinhardt Schneider, and Shanoa are VERY niche characters, and Shanoa is further damned by having enough visual similarities with Bayonetta that a more casual Smash fan who hadn't played their games could probably confuse them onscreen, which wouldn't play well since Bayonetta is already in Smash Ultimate.
Sounds like you'd love Serio's Castlevania Fighter though.
(God's sake, is that even still around?)
It's good to have dreams though. Welcome to the forums, by the way.