OK, to clear up my thought process here, now that I'm puzzling this together mentally, this is how I think it went down, step by step, and a bit easier to understand (mostly for myself, cause that first post confused myself). Since Pramai is in between Jigglypuff and ROB, I am actually sure it is counted a Brawl newcomer.
A. - First character draft:
All characters that ended up in Brawl save for Jigglypuff, Toon Link and Wolf had been decided on as the initial roster. This also might have been where the Pramai-character has been developed in, but it must've been dropped very early in the development of the roster.
A.1 - Pramai:
If Pramai was not in the first character list that had been developed, it has been added somewhere in between A and B.
B. - Second character draft (veterans return):
This is where the characters Jigglypuff, Dr. Mario, Mewtwo, Roy and Toon Link had been created (Toon Zelda/Sheik maybe as well), most likely in order to beef up the roster that was perceived as too small - by Sakurai, Nintendo, whoever. The development team decided to re-introduce some of the veterans that they had removed from the initial roster, and they also re-skinned Melee's Young Link as Toon Link.
At the very latest somewhere during this phase, Pramai had been dropped (maybe in favor for the other 2 Pokemon), and Dr. Mario was removed in this timeframe, as well. If Toon Zelda/Sheik had been included in this second draft, they have to have been removed here as well.
C. - Bye, Roy:
After the scrap of Pramai, Dr. Mario and possibly Toon Zelda/Sheik, the idea of character jingles had been removed. This also the stage of development where it was decided to remove Roy from the roster.
D. - Mewtwo Problems => Wolf:
This stage of the development was very close to the release. I even would go so far and think that it might've been one of the reasons why the release date was postponed. Mewtwo seemed to cause some serious trouble to the development team. They wanted to keep him, but either due to some gameplay aspect or some issues with Game-Freak, Mewtwo ultimately was scrapped. This why Mewtwo also has the most leftover data. This was also after the victory jingle idea had been scrapped.
Since Mewtwo was gone, the development team needed another character to fill the spot. They drafted Wolf, Dixie Kong and maybe Toon Zelda/Toon Sheik (if she wasn't in the B-roster), and it was decided that Wolf was the best choice for some reason (maybe it was because of character preference from Sakurai, or because he felt that he would bring the biggest variety to the roster in comparison to the other 2).
EDIT:
OK, I think I'm done with editing my post.