Well, considering the fact that Shiek's making it back in for some reason, significance to smash IS a factor, and Original 12 at least has some merit since it hasn't been broken yet (sure you can mention Ness almost leaving, but he didn't, and then with his return to brawl he became even more of a mainstaysecondly, what I meant was that Earthbound is still the most notable entry in the Mother series, in spite of Mother 3 technically being the most recent game. Actual US Release, recent reasonably successful virtual console release, isn't that enough to justify Ness over Lucas?
Also... HOW THE **** DOES VILLAGER FILL THE SAME NICHE AS JIGGLYPUFF THAT MAKES NO ****ING SENSE! Floaty aerial character? One, I see absolutely nothing pointing towards him being an air based fighter, sure, he may have an air game, but you might as well say he's more like Mr. Game and Watch. Two, they're obviously completely different character I'm not even sure how you can argue otherwise. Three, a need for unique characters? Well, then there's absolutely no reason to cut Jigglypuff then =P
I see absolutely no evidence that villager controls the air a way even remotely similar to the way Jigglypuff does, and with their completely different specials, they have completely different tools and stuff at their disposal. Saying Villager covers Jigglypuff's niche makes literally no sense at all. We might as well say Rosaluma steals Ice Climber's niche while we're at it, that's how big of a stretch that is.
So, Jigglypuff could possibly leave (not a big chance, but it's POSSIBLE) but being replaced by Villager isn't a reason. Ness has 0 chance of leaving however, and I would think that would simply be common sense at this point.