I sense some degree of frustration in Gunn's language. As head of DC Studios, not knowing how audiences will receive two different versions of Batman existing concurrently is certainly some cause for stress. And he's probably having to think about this in ways he'd rather not have to.
If the goal is for the DCU to be a sustained and successful mythology, Batman has to be a key player in it. You can't position to create a DC universe without him in some meaningful capacity. You just can't. Well, if audiences aren't receptive to The Brave and the Bold because they prefer what Reeves is selling, that's a tough spot to be in if your Gunn. He has to find some way to make both of these work, and there's simply no knowing what will happen or what audiences will think until they actually just do it.
Which is why I truly believe the path forward here for them is to lean heavily into the Bat Family and the more heightened fantasy/sci-fi elements of the Batman mythos. If they sell it as a "Batman, Robin, and Batgirl Movie" and not a "Batman Movie," that might be the hook they need.
With all of that said, unless The Batman: Part II is too big and successful to ignore, I think this is the end of the road for Reeves' version. I really do. If it's obvious that audiences aren't on board with two different Batman franchises happening at the same time and Gunn has to choose between his version or Reeves', it's pretty obvious what he's going to do.