League of legends has a neat tool:
It auto records the last match you played, so people can watch it.
I think if wow had a feature like this, it would make it possible to more accurately judge how a player is going to perform in your group.
Given the state of the game and how little they time they spend in actual development… can’t say this would ever be a thing.
Just keep guessing. If you see the OP, invite them to ur group and then post here about how well they did!