Originally Posted by
bat39
Agreed. It is headcanon on my part. Though many of those films had the same voice cast so you could argue they're kinda officially part of the same universe.
The real difference is that these were all standalone movies, regardless of whether or not they were set in the same universe. The ''shared universe'' concept only really becomes a factor if the movies go out of their way to include references to other movies. But it is possible to have movies set in the same universe/continuity that exist independently, albeit without contradicting each other.
Hell, a lot of the time, the DCU operates this way in the comics, in practise. If you wanna go strictly by the chronology of the Post-COIE DCU, Batman had not only met Superman but was probably already a Justice League member by the time of TLH...but that has zero relevance to TLH, which is a noir-driven story with nary a 'superhero' in sight!