I think as long as they keep the non-connected universe stuff to just the Batman and Joker films, people will be OK and not get too confused. If they go beyond that, it could be problematic. Audiences are much smarter than studios give the credit for. Sure, no amount of marketing clarification will completely have everyone understand but by and large most knew Joker wasn’t connected to the DCEU and people weren’t asking where Ben was in the Batman. Heck, the best thing the Flash might have done is establish different cinematic universes exist for DC.
Plus The Batman and Joker were a few of the only DC films to make a profit recently so that alone helps ensure they move forward with their sequels.
Plus The Batman and Joker were a few of the only DC films to make a profit recently so that alone helps ensure they move forward with their sequels.