Well considering how far we are from the release, any speculation will be of the wild sort so I don't see how anyone can throw out percents in the way they are. Either way here's my own personal opinion on potential cuts from Brawl.
1. Wolf - A great addition but also a late addition to increase roster count. While I don't think being a clone negates any possible return, the fact that Fox has two clones is iffy to say the least. I can imagine them combining Wolf and Falco together and getting rid of the other and considering the fact that Falco has more history/less of an after thought suggests Wolf possible removal
2. Lucas - Mother is a great franchise with a cultic fan base but stagnant none-the-less. While Ness is a international icon, Lucas is more limited by his region and didn't see a more distributed release despite more fan awareness. Now that doesn't guarantee anything either way but as a simple Japan only rep (assuming Sakurai has a fancy list that has to have Japanese rep marked off) he doesn't add anything really and he really isn't iconic as a character in his own right (though that could be my own misplaced opinion)
3. Snake - This is more in lines with business dealings. I'd include Sonic as well but considering the fan popularity for the hedgehog as the "Rival of Mario," I there is more incentive to close the deal in another inclusion of the character. really when it comes to these characters it's all about fan support and business relationships, so there is no sure fire way of guessing if they'll make it in or not. (This exclusive deal Nintendo has with Sega for Sonic means little IMO, it shows a good company relationship but gurantees nothing)
4. Jigglypuff - This character has been hiding behind the miraculous original 12 for the longest time but that argument suggests Sakurai has some kind of status quo he must hold, as if Sakurai has a list that states: must have retro character, must have japanese exclusive, must keep original 12. I mean he could but I doubt it. Jigglypuff may have seniority on her side but she lacks significance outside Smash bros as in she doesn't really represent the series in outside media. Also something to keep in mind is that she was also was a late addition to the brawl roster and was at one point not going to make it in. I know a lot of people consider Lucario to be the first go-to character for removal for this game (and he could) but Lucario is still being used to represent the franchise. Of course its really hard to predict in which way pokemon will be represented this next game but I can see Jigglypuff as potentially being cut.
5. Toon Link - This isn't because of the stage but rather simply because Toon Link isn't a necessary addition to the Zelda line up, and his place could be filled with a potential new representative. I certainly hope I'm wrong about this though.
as for other characters being suggested: I can see why people are concerned about Ike and PT being cut considering their placement in two of the more represented series but I think the characters have enough following relevance to maintain roster placement. Ike's return really depends on whether or not a heavyweight Fire emblem rep can hold enough significance to replace him. I keep seeing Chrom's name thrown around with the whole stage confirmation and whatnot (and I'm not saying it's not possible) but IDK it just seems unlikely that they would replace Ike considering his has more representation of the series and has some seniority over the new swordsman. Of course trying to guess who will represent Fire emblem this time around (besides Marth) is near to impossible, there's way to many factors to consider
Pokemon Trainer on the other hand has a few things going for him, while he's not totally in the clear he isn't as questionable as some other names people are throwing around. The thing most people fail to notice is that the Pokemon trainer's popularity is not his own but the accumulation of his pokemon team. The first gen starters are the most popular set by far as characters like squirtle and Charizard are still making dents in polls as far as popularity is considered. Plus The specific trainer model (Red) has been revisited more times than any other main character (about 7 appearance I believe) within the pokemon games. Furthermore I don't see him being removed for the mechanic alone. That is competive thinking logic, which isn't necessarily in line with Sakurai. The Trainer showcases the essence of what pokemon is, and I don't see Sakurai removing that. Now if another trainer is revealed then I'm assured that Red will be out, I just don't personally see that happening.
Of course all of this based mostly on personal opinion so I could very well be wrong on the majority of it.
Ike definitely won't go easily, though, as he is quite popular among FE and Smash fans alike.