Do the actual perk points return to the unused perk point pool when a skill becomes legendary or are they stripped along with the perk? If not what happens if you have already redistributed perk points from a skill using Dragonborn?

The perk points return to the unused pool, you have to reassign then.

Wow nice! Ty Logan and ty Bethesda! Wonder what that could mean for what is coming. Maybe the Ebony Warrior is just the start?