So far we really only have a very few mentions. One was about Dick's relationship with Helena causing "tension" in the Bat Family as "more and more" people from Gotham get involved. The other mentions are those quoted by Claude. We also have a few throw away remarks here and there, like King talking about chatting with Fletcher over drinks about Dick and Batgirl.
So, I think it is looking good that Barbara will be involved. Which is no surprise. All those remarks about redheads in
Grayson are surely there for a reason. But, we also know that Damian will be involved at some point because Seeley said so. Oh, and there's going to be something between Selina and Helena, evidently.
Now, if you want to stretch the point, they have talked about doing "lots" of stuff for the Grayson 75th, and that would be hard to do without a lot of other characters. And, as Claude says, with Owlman running around in
Justice League there is unfinished business there, as well.
So, things don't look nearly as restrictive as all that.