I'm pretty sure we will get two Donkey Kong series newcomer. Why? Well, DKCR was released after Brawl, so Nintendo couldn't know DKCR would sell that well: (DKCR has more sold copies than DKC2 & DKC3, only DKC having sold even more copies than DKCR)
Beside that, the franchise has many titles to look at: 11 games of the main series and another 13 spinoff-games. This makes a bunch of games, doesn't it? The series is relevant and with the last game being that well received, there is no way they won't add another DK character. I also guess they will add a character to later on push DKC:TF a bit more as DKC:TF will already be out before SSB4 and therefore SSb4 can get people interested again later on in the game.
5 characters would be like Christmas for me(Donkey Kong, Diddy, Dixie, Cranky, K.Rool), but I'll stay realistic. We can get 4 characters, 2 veterans and 2 newcomers and that's it at least for this time.
However I hope you will edit your analysis again on the DK series because of the new facts related to DKC:TF as this increases the chances of Cranky. We can consider that Retrostudios shared the information on the playable characters with Nintendo and on that way Sakurai could already know that Cranky will be more important than he was in DKCR.
Still, I like your analysis on every series so far. I'm also interested in reading your analysis on the new series as I would really like to know your opinion on the topic of new series.