-Matt Reeves and JJ Abrams are long-time friends from childhood and have collaborated on a lot of stuff before.
-Matt and JJ have both signed exclusive contracts with WB and HBO MAX to make exclusive content, movies and shows, for them; especially projects related to the DC Universe. As far as I know they're the most prominent creators to have gotten this deal for DC characters. Matt has said he'd love to collaborate with JJ again.
-Reeves is producing a Gotham Central show. Gotham Central the comic features Crispus Allen, who becomes The Spectre.
-JJ is producing a Justice League Dark show that as far as we know won't be connected to the old DCEU.
-Batman has made several crossovers with the JLD in the comics and animated movies, and a notorious obvious connection is his platonic friendship/relationship with Zatanna, which JLD will presumably have on its roster.
I'm just saying that literally all the pieces are there for an Abrams/Reeves DC Universe. An episode where Rob's Batman appears in the JLD show would be cool, or having Allen cross one show to another.