In DC's case, I think they'd actually be better off ignoring the idea of a shared universe anyway.
There's no scenario where the DCEU comes out looking favorably in comparison to the MCU. The MCU has almost two dozen movies to its name so far, and not a single one of them has been a failure. No one else can say that, not Indiana Jones, not James Bond, not Robin Hood, not Star Trek or even Star Wars (Ewok Adventures anyone?). We talk about Thor 2 (and Iron Man 2) as being bad films, but they're only bad when set next to other MCU movies. DCEU on the other hand, started off with a film that got mixed reception and (other than Wonder Woman) has just gone downhill from there.
There's no saving the DCEU, it's never going to be accepted by the general public in its current form even if the next five movies are all quality.
So instead of trying to make this failed DCEU thing work out, just make good movies. Simple as that. No need to jump through the shared universe hoops that Marvel does. The only reason Marvel did that in the first place was because no one gave a damn about their characters. No one was gonna line up to watch Ant-Man or Thor without an extra hook to reel them in. DC never needed to do that, their big characters have been household names for generations and will draw an audience on their own, easily. DC has saddled themselves with a handicap they never needed, because they mistook that complication for success.