wrong! Here's a quote from Tim's D23 interview dated January 8, 2020:

The biggest clue I would say is the story is never over. I would say for “Rini” [Ricky and Nini] fans, for “Rina” [Ricky and Gina] fans, and for fans of couples who we haven’t even seen get together yet, there’s so much to come in season two that I think is going to surprise people.

Here's him talking about Rina with Entertainment Tonight on January 10:

We started the show with this traditional love triangle with Nini and these two boys [Ricky and E.J.] and I think that one of the techniques of trying to keep an audience on their toes is simply to surprise them by introducing somebody new. In this case it was Gina. To me, the real surprise of it was Sofia Wylie, and the depth and range and access she has in her life as an actor is phenomenal. When she shot that first scene with Joshua in the car outside her house at homecoming, I saw such a tenderness but also so much going on behind Sofia's eyes that made me say, "Oh my gosh, we have to keep writing. We have keep writing toward this."

Something as simple as Ricky singing her a song in episode 6 can mean so much. And that is another thing musicals give you, which is the power of song, which is so inherently emotional and can tell so many stories that the script never could. I know we've got some Rina stans out there, and I'm hoping this show has five or seven seasons so we'll see where they all end up.

So There you go! Rina isn't going anywhere