I don't think it is Justice League International even though there was a hashtag for it. I think this is the team that will stop Trinity War. Batman is supposed to get the box from Pandora so we know he is going to have a lot going on. There is the whole Superman/Wonder Woman thing, etc.
These characters kind of pull from all over.
Here is a follow up question though: If Batgirl and Black Canary are on this book, does that mean they are still in Birds of Prey? Wasn't Black Canary a fugitive? Do you think they can both be in two teams together? I hope this doesn't spell the end of Birds of Prey -- I'm just starting to like it.