Some things never change.
Greg Berlanti, executive producer on both Supergirl and The Flash, has again been asked whether the two will cross over.
And he's given his usual answer: He'd love to, but that's not entirely his decision.
“I would love it, a lot of things would have to go right and people would have to say ‘Yes,’” Berlanti told EW at the Television Critics Association. “It would have to figured out very soon. It would all have to be figured out in the next month or so. As it remains right now we’ve talked internally about how cool it would be, but we haven’t had official conversations. [The CW chief Mark Pedowitz] is supportive.”
There's a ticking clock, in part, because both Supergirl and The Flash are filming episodes that will air late in their seasons...and Supergirl's order is only twenty episodes, not 22, meaning that they have a little less time to work with.
From the start of the season, CBS has been resistant to a crossover, which wouldn't be as practically easy as The Flash's crossovers with Arrow. Not only do the series air on different networks, but they film in different cities (and countries), rather than on the same lot.
Supergirl's next episode airs on January 18 at 8 p.m. ET/PT on CBS. The Flash returns on January 19 at 8 p.m. ET/PT on The CW.