Except, one, the changes for Climaxes are mostly fixes rather than blatant balance updates (unless you really want to get technical about 2 damage for Raiden).
Secondly, there's no guarantee that the new characters would get endings, especially when you consider only Saiki seems to have had any effect on the story (obviously since he's the Big Bad), and his ending would either be the generic "Big Bad wins everything" or just him losing...again. At best, they might give Billy a generic ending of his own.
Thirdly, there are no new characters for Climax that the console version hasn't already received, unlike in CS2 where they got Platinum early.
And for the final time, and I'm sick of having to repeat myself, it's extremely unlikely we'll get more characters, and for damn sure we aren't getting better netcode for the same exact game. We'll probably get a title update for the Climax fixes and that's about it. People really need to stop treating Climax as more than it is. The only reason I'm excited about it is because it means more footage of more players actively playing the game, which can up my own playing.