So are they adding mastery 6-7

its on the PBE for testing currently!

Yes. But it appears to be extremely dumb to get. You have to unlock it in hextech boxes from what I'm seeing.

Next patch, so I've heard. Actualy a neat thing, all you have to do is getting S again with champions. So grabbing your main to farm those is welcome.

Unless there's some limit to those tokens that they're setting to avoid that.

Why are you surprised/confused? They said that the first 5 were just to test the waters and see how it well it would work.