Some info from gonintendo.com:
Sakurai: Not enough time to bring back every Smash Bros. character
June 19th, 2013 Posted in 3DS, News, Posted by Brian, Wii U
Super Smash Bros. director Masahiro Sakurai was recently asked if all characters who have previously appeared in the series will be back for the Wii U and 3DS games. The short answer is no.
Sakurai explained that the team simply doesn’t have enough time “to fully recreate every single character who’s been in Smash Bros at this point.”
He said:
“I can answer that: no. We don’t have the time to fully recreate every single character who’s been in Smash Bros at this point. Adding new characters is not a simple addition – it’s really multiplication. The amount of work, adding a character is multiplied and becomes bigger and bigger as you go. We can’t because of the amount of work it takes. However, I do believe I understand that each character has its own set of fans out there who really like that character. So we’re not going to cut characters out of the way, we’re going to put in as many characters as we can, we really want to do that, because it’s good for the fans and good for all of us. But in the event that we do have to cut some characters, I’d like to apologise in advance to those fans.”
http://nintendoeverything.com/126065/sakurai-not-enough-time-to-bring-back-every-smash-bros-character/
It seems to me that he does not want any cuts from Brawl, but that they may happen due to time constraints. Notice he says not all characters from PREVIOUS smash games, and not just Brawl, so he is most likely talking about Pichu, Young Link, and Doctor Mario (I think Mewtwo will be back and Roy has a chance.) He was also asked about Melee and Brawl (not just Brawl) in the other "cutting characters" quote.