I just noticed something else: in order to accommodate the DLC characters, the select screen portraits have been stretched horizontally to fit a 14th row. It's not a big deal, but if you look closely at the portraits everyone is just a tiny bit too narrow. Unless the select screen is mechanically redesigned through a patch, there isn't going to be room for a 15th column. I thought the borders of the portraits would move inward to fit more characters, in which case a 15th column would be feasible, but instead the game simply stretches the portraits horizontally.
Here's what a regular portrait looks like:
Instead of making room for additional columns by moving the borders in, like this...
...the game stretches the portrait like this:
It's barely noticeable as is, but it's going to look way too unprofessional if we get at least three more DLC characters.