I am not a fan of Katy at all but she did seem genuine in what she said. I don't know why people keep trying to cause more tension between them. There's been a few shady comments over the years but I doubt we'll see much more than that.
That said, I think a collab could work. Not if Gaga "reverted" back to FameGa, but if Katy matured her sound a little bit. If her sound on the next album falls more in line with ET or something, I could see something working for sure.
Yes, talking about the willingness to work with whoever you could when you were starting out definitely makes sense 4 years later. I don't even think her vocals are on the second song, didn't she just write it? You sure clocked the thread good.