To be fair, Rogue used to be pretty similar to Evo Rogue until about the 90s, so it wasn't exactly a mismash, but Evo and comic Kitty are two very different characters, so it'll likely be harder for the writers to incorporate the two beyond the occasional reference.
I also have to wonder about the story changes. If they're following the comic, then Kitty will have only manifested her powers mere hours before meeting the X-Men, but here she'll be eighteen like Null was, but unlike Null, she's immediately thrown into the deep end with the whole Phoenix and Hellfire Club shenanigans while Null had an entire season to get used to things, so it'll be interesting to see how her character handles that.
I imagine she'll be a lot closer to a full mental breakdown here than she was in the comic, and that her prior life before manifesting her powers will have a lot more influence on her character.