There was a time not long ago that James Gunn and Matt Reeves were content with his The Batman franchise staying separate from Gunn's new DCU. And with the delays with The Batman Part II, we've speculated that perhaps the two are trying to find ways to incorporate Reeve's series with Gunn's Superman.
And it appears this may be the case. From the mouth of Matt Reeves:
“It really comes down to whether or not it makes sense. What the future brings, I can’t really tell you. I have no idea right now… I don’t know, we’ll have to see where that goes.”
This makes even more sense with the DCU's planned Batman movie, The Brave and the Bold, being temporarily shelved as well.
Source: Dark Horizons