How are they lying to fans? Nowhere has Gunn said for certain the movie ends in his DCU. In fact, he recently said that Blue Beetle was the first DCU character audiences would meet. Chances are Miller, Momoa (as Arthur, could be Lobo), Gadot, andI try to not look at corporate's impression of a long-finished film that pessimistically. That idea seems solely based on very recent fandom reaction.
There was no predicting how the box office would turn out until now. If they knew it was going to fail and put it out aways and lied to the fans, well, can you prove that?
Clooney
If The Flash was successful, maybe he would have incorporated it but the movie ended in a way he doesn't have to.