I really want this to happen. As much as it would be cool to see Luffy physically be the one to knock out all four of the Yonko, I just don't see any reason for Big Mom's character to be in the story going forward (and no, don't mention Elbaf. I don't think she is needed at all for an Elbaf arc).
We all know Luffy is going to be the pirate king, but where would the fun be if he didn't have rivals? Yeah, we know they aren't going to make it, but in context of the story, seeing Luffy fume because Kid has x amount of Ponyglyphs and is close to Laugh Tale would make for some great comedy moments.