It's a completely separate function that Margaret will get at some point in Labyrinth 3. Various persona skills will start being highlighted in blue, and you can spend some yen to turn that persona into a skill card.
That sounds super neato, maybe I should stop spending so much time trying to figure out who I want for my fifth party member before starting Labyrinth 2 and get a move on!
Also, Skill cards are totally one use right? I got the one from the first Labyrinth, revive I think it was, but been too paranoid to use it only to swap out that dude and lose the skill.