Well you can already ask questions on pokebase about tgc so that would be like
How rare is this card?
What does level x mean?
And you can ask rate my deck questions on the battle subway, though they are likely not to be answered, just sit there for eternity.
There are only currently two people (Trachy and Rio that ask and occasionally answer tgc decks).
But this has been suggested (One extra section) I remember josh asking for this in the past it would also include spin off related questions and teams.