Yara is an addition to a “Family” that outside of Diana herself has never been very popular or well known. Jace is not, Nightwing, Robin, Batgirl, all of these are far more well known and popular. It’s disingenuous to pretend the two are anywhere near the same level of popularity.
Not with Batman they aren’t. Reeves Batman seems to be a very traditional take, and everything points to them being fully invested in whatever he does. Keaton Batman will be mentoring Batgirl and maybe even Batman Beyond down the line. There’s been no inclination they’re considering what you’re saying, and everything else starring Batman features Bruce in the titular role. Their “Black Panther” attempt will be Static, GLC, or the Superman reboot.
Jace could easily show up in the CWverse, that’s true, but I doubt it will happen. If the CW gets Batman I pretty much guarantee it’s going to be a traditional Bruce Wayne take. Why? Because Bruce Wayne is still insanely profitable and popular. He’s singlehandedly keeping DC afloat in terms of comic sales. Their attempt at replacing Kane with Wilder has been a flop, doubt they’ll try something similar with Bruce.I mean, if we're talking Superman & Lois, where Jon has recently debuted, we can look at the CWverse. It's really not unlikely at all for Jace to eventually show up there. Luke exists. Lucius existed.
It is interesting to compare and contrast Jon's relationship with the Superman Family with Jace's relationship with the Batman Family and the fandom as a whole. Jon has a very easy concept to get with, whereas Jace has to earn his stripes like Terry McGinnis did while facing hate from all angles because of a multitude of factors, some unfair.
Jon is, like, totally not better than the OG Superboy, though, so it's no wonder he didn't last long in the role.
They’re doing all this wild stuff with Superman because Clark hasn’t kept up with Bruce, while still being popular and profitable for them. Hence the film reboot, this stuff with Jon, etc. Batman isn’t in the same position, especially with a Bruce Batman film franchise poised to take center stage for the next decade. Maybe you’re right and I’m wrong, maybe what you’re saying is indeed how it will play out and after Reeves and Pattinson are done we’ll get a Jace Fox Batman film, but I doubt it honestly. Feel more like they’ll just keep rebooting Bruce Batman forever.