Do you ever wonder which smash 4 newcomers only came back because they were bringing everyone back?
I imagine most of them would have returned. Generally the cuts from game to game up to that point are derivative, low priority characters with some exceptions being Mewtwo (likely low priority because of how many Pokemon are in the game) and Snake (he's a guest, so he can't really be judged the same way).









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It's hard to find equivalents in Smash 4's roster since I think they added very "efficient" picks, many of them representing a new series and the derivative characters, later to be deemed echo fighters, being a lot easier to construct. I don't think their ease of access makes them immediately safe though, just because we've lost clones in the past. So I think Lucina and Dark Pit, albeit sort of a copout, are some of the first to go.
Then there are lower priority characters, and those who feel more expendable because they're part of larger series. Corrin is the obvious one, and although I feel generally that a first party DLC character ought to just be in the base game next time, FE would be a prime candidate for cutting down and I believe Robin would continue to take precedent. Maybe a bit controversial, but just to parallel the trend of characters added late in development being cut in the following game I'll say Bowser Jr could become our Mewtwo. He almost missed the boat, and he's from a series which is otherwise going to receive new content no matter what. He feels way too important to lose on paper but he just makes sense if we're contextualizing through the previous games. Side note, Pokemon seem to have been unfortunate in the past but I think Greninja is on the safer side anyway.
Smash typically doesn't cut a sole representative for a universe unless they have to. Ice Climbers ran into a technical slump and Snake... we don't really know what happened, but it's safe to assume guests are somewhat expendable by default. I don't see many of our new guests being cut, but perhaps Cloud may have had less luck and been considered a loose end due to his minimal content (at least at the time) had the goal not been to bring back everyone. Assuming what we've heard is true and he may have been one of the last characters locked down for EIH, he may have missed the boat at first.




Maybe a bit uncreative, but feels within the spirit of the cuts we've seen in the past. Clones, lower priority characters from larger series, and a major third party addition who slips through the cracks. I can't really think of anyone else on the roster I'd have considered expendable - especially since Ultimate is able to build on Smash 4 more directly, and because the others were presumably high priority or are carrying their series on their backs.
What's funny is that NOW I don't think all, or even most of these characters will be cut. I feel as if Bowser Jr is safe, Lucina is kind of a staple now, Cloud may as well come back since SE has four characters on the last roster and Dark Pit might just be piss easy to add anyway. But putting it in kind of a "historical" context, if Smash 4 to Ultimate had progressed normally, this is a pretty accurate parallel to how it went down the last two times.