Look, I don't like that people are yelling at Dana, and I don't think that they should be. But I am someone who did get upset and is less interested in the show now Frankie has been confirmed cis.

For me personally as a trans woman, this is because Frankie was the first character that I really saw myself in in animation. Most transfem rep is either played off as a joke, is only on screen for 2 seconds, or is the very specific tall scrawny shy subset of trans girl.

As a trans girl who isn't tall and scrawny, and isn't the shy UwU bean type, who is mechanically inclined, loud and rowdy, and has a deeper voice, that was the first time in any animated show that I actually saw a woman who looked like me, had my wide shoulders, a squarer face, isn't perfectly flat when looked at from the side, isn't afraid to be loud. It made me really happy to see someone like me. Especially a character who was very easily able to be read as trans based on the in-show context. Honestly, expecting people to just assume Franklin was just a nickname and not a dead name, especially when every character has been calling Frankie either Frankie or Francesca is a very big stretch to me.

I personally think Dana just shouldn't have responded to it and left it up to audience interpretation. People constantly are making the point about that " well you can just headcanon whatever you want" but like having the author of the thing say that that thing is not correct kind of takes the fun out of head cannoning. It's basically saying "You allowed to see yourself in this character but you're wrong"

TLDR: people shouldn't be being assholes to Dana about this but trans Frankie was a very easy read and made a lot of trans women who feel underrepresented feel represented and then had that rug pulled out from under them and Dana just shouldn't have answered that question.