Hmmm. Very odd. Usually hydraulic failures result in the clutch not engaging. This sounds like it's engaged and the piston of either the master or the slave has seized. I can't see it being a problem with the plates as usually when something happens with the friction material with them it usually results, at least at first, with a dragging clutch. If the centres had ripped out of the plates the hydraulics would still work OK and it tends to cause a hellacious ratcheting noise!
What might be worth trying is opening the bleed nipple on the bleeder hose. If it pumps out a squirt of fluid and then the clutch disengages, (Leave the bike in gear, engine off and push it fore and aft to see if there is drive to the crank from the wheels.) if there is then it would point to a problem with the master cylinder and since that was the thing most recently touched I'd say it's most likely to be what the problem is.