Cross-team chat can be controversial:
Sometimes it can be full of people generally trying to help other players or just to chat. I honestly have seen that.
On different occasions it becomes just a place to went.
Or it can be just silent.
It's still being considered.
And while we allow cross-team chat - we have to keep the ability to do a quick report. Because support ticket takes much longer time than just two ckicks needed for the report, and not everyone would bother with it.