And yet I still don't buy that Reeves would prefer to develop anything outside his own universe where he has set the template and he can have far fewer restrictions. And like I said before, I sincerely doubt that if the project was to be part of DCU from the moment Gunn took over, since he didn't announced it with the rest of the slate, which included things that didn't have anyone at the helm.
I can 100% buy that Reeves would prefer to develop it outside his own universe if developing it outside his universe meant more freedom for him to do certain things in the sequel, especially as it pertains to Joker and Riddler. Also, you are forgetting the other part of the equation here which is the showrunner, and if he simply realized
it'd make for a better show. In the process of meeting with people, it's 100% plausible that Reeves immediately came to realize that there were 2 avenues to take with this show:
1. Do a show where the showrunner would be able to use as many rogues as they wish and do all sorts of interesting things with them. Which is the pitch that'd probably attract the most talent, since the entire appeal of doing something like an Arkham show in the first place is to play around with the Batman villains and reinvent them and their dynamics and their relationship with Gotham yourself.
2. Do a show where they'd only be able to use 2 rogues which would be micromanaged since Reeves probably already has very specific things in mind for them in the sequels and then only be limited to use a bunch of D-listers which are gonna be grounded to the extent they'd lose all the fun of even doing a genre show like this in the first place. Which is the pitch that'd probably only attract showrunners with extremely limited experience.
Reeves probably realized the former would be a better show, so he chose to go on that direction instead of making a worse show with worse talent just so it fits on his universe.
Also the slate thing is such BS because he didn't announce Peacemaker Season 2 in the slate either. Doesn't mean it's not coming or not being developed or that he didn't already have it planned. The slate seemed to be more about the projects Gunn directly pitched to Zaslav and WBD execs as part of the 10 year plan, and since Arkham was pitched
to him (meaning he didn't come up with the idea of it being in the 10 year plan himself) it didn't make sense to put it there. Also, since it's Matt's baby and Matt is in charge of it, he can't /guarantee/ it'll actually come out because it all depends on Matt's disposition to keep developing it because Gunn isn't gonna go out of his way to do it himself with all he has on his plate already. The others, on the other hand, are his babies and he'll make sure they come out.
If anything, had it been Gunn's idea to move the show over to DCU, wouldn't he have announced it himself then on a big way instead of doing it a random Sunday on Threads at the end of the year, possibly an entire year after he decided it was gonna be DCU?
If Penguin does well and the DCU doesn't, then yes, I can see them continuing with more. This is literally what I said. Otherwise Gunn said since day one that he wants them all connected, movies, shows, animation, even video games, so I can certainly see him not wanting to greenlight anything outside that universe from now on. Even more so Zaslav has said since day one that he wants the MCU model and that it doesn't make sense to not have everything connected. A big indicator is that there hasn't been any Elseworld project being developed since both of them took over, not even the black Superman film that was initially reported that it was still happening, back in January.
Francis and Keanu literally said that they're still being allowed to develop Constantine 2. (I've repeated this point to you so, so many times and it's astounding how it's still going over your head) And Gunn literally confirmed there'd be more big videogames set outside the DCU (which is again, something that right now he could easily have terminated especially because Kill the Justice League is about to be a disaster) as well as animated movies and shows. If there's any PR spin they're doing is the whole "It's all gonna be connected"; it's not. Most might be, but not all. And in the case of The Batman spin-offs shows it'd be pointless to cancel them because:
1. It's streaming. You can quite literally put The Batman spin-offs on a separate category on MAX and no one would be confused even in the slightest.
2. They're already doing 2 movies and 1 spin-off streaming set in that world with a Batman that'll be different from DCU Batman so like, the "worst" in regards to connectivity is already being done. 1 or 2 more streaming shows wouldn't possibly hurt.