I really don't see Mint going to Phase. From what I understand of her, Hololive would be best, with Vshojo a semi-distant second. Phase doesn't really have much to offer with what she wants to do, in addition to the fact that if a vtuber can handle being indie, that's the way to go.
So unless Phase is indeed investing a lot more on the whole idol side of things, and Mint will be the driver for it, I just don't see her joining.
Then again, I have a history of making predictions that end up the opposite, so... fucking hell, are we really getting Pomu and not Selen or Zaion? What a weird world.