Sure, but Meg was always headed in that direction. Barb and Arryn are different people. Barb's career is in no way dependent on OF. If she leaves RT, she's most definitely not going to go all in on OF.
When did either of them say they'd never do a candid collab set??? Follow Barb on social media, though I don't keep track of everything she does and care very little of what Arryn does aside from this and Rwby
I can't remember which one said it, but I'm pretty sure someone posted a DM they had asking about it, probably from Arryn. This was like, very near the beginning of both of their OF careers.