I’ve a suspicion - nothing more than that, and I may well be proven wrong - that WB will retool their series over the next few years. People can dismiss the Affleck-leaving stories as clickbait but he has been at best non-committal over the last few months. Then you have the Joker origin film that won’t feature Jared Leto, while it’s far from clear that the planned Batgirl or Nightwing films will be in the same continuity as the current series.
If anything, it’s looking like they may take the same approach as their standalone animated movies - some may feature the same actors in the same roles, some may be direct sequels but they will not necessarily all exist in the same overall continuity.
Yeah, I'd heard about the Joker origin film being unconnected, but not so much about Batgirl. (Not keeping track, I hadn't even heard about a Nightwing one).
While I said series, I meant more in the way that my friends and I would like the DC based movies to continue as I have enjoyed most of what I've seen so far. Going off older films, I'm quite used to them not being linked so that wouldn't bother me.