Well, in any case it sounds like you're gonna be "in there" soon and find out for sure. But, I'm gonna guess it is the TO bearing or possibly the pilot bushing. (I once has an input bearing on a M21 go bad - sounded pretty bad like the video - but it was worse w/ the clutch OUT than with it depressed, For What It's Worth (FWIW).
Might as well...
...have a new disc on hand when you go in there - sorta mitigates the trouble of going in there in the first place - call it a "clutch overhaul" - freshen everything up at the same time.
And...unless the clutch PP or FW surface was burned or worn as result of metal to metal contact/damage to the PP or the FW, there's no concern for "turning" either. The new disc will quickly break-in after a 100 miles of so of use with normal driving. (The Veleo PP is slightly beveled in toward the center.
So, you want to avoid any drag race type clutch engagements until the disc has a chance to assume the shape of the disc/FW surfaces.)