@ AMazing Ampharos - We had 5 cuts between Melee and Brawl including one character with a unique moveset that was popular (Mewtwo). I would say that is a serious cut. Could get the same here.
I think you overstate the cuts from Melee (Does Doctor Mario really even count as a cut?), but either way, 5 isn't that big of a deal. I see some people talking like we're losing half the cast, and that's just not likely at all. I mean, including all transformations as their own characters, Brawl had 39 characters. Let's say they cut 8 of them. That means that 31 of them return which is an awful lot and will leave most people with tons of characters who will be familiar. It could be even fewer. If we see the loss of let's say Pokemon Trainer and Ice Climbers for technical reasons, we lost four movesets but really only two characters, and most of us don't end up much worse off for it. It sucks for people who loved those characters, but I think most of us have love for several different characters so even if your #1 didn't return, you almost certainly have someone coming back you were fond of.
I also might point out that Ice Climbers didn't really work in either game. I always called them the Ice Grabbers, and after about the 20th time I lost a stock to an infinite, I was out of love for the character. If they were a character that didn't return, I think most of us would really be better off to breathe a sigh of relief than to be upset; it's not that they couldn't be made better this time, but if they were gone, we sure wouldn't have to worry about it.
Also, if technical limitations are a problem, I can always just take the selfish approach. I play Mr. Game & Watch. I think only people who got into hacking Brawl really realized just how simple he is, but from a technical standpoint he's something like half as complex as any other character. Add in that early concept art that had him as a small background character (was that ever confirmed to be official?), and I'm sure liking my flat buddy's return chances. All I need is a good screenshot of him and my favorite turtle, and I can finally have an avatar update after all these years.