I think it's a calculating mistake for Zack Snyder to not make the effort to make the TV universe canon with the movies. I've been watching The Flash, and Supergirl hoping those characters would make appearances in the films. Snyder official let it known the TV stuff is from another Earth, which to me lessons my investment in those characters and make me less interested in what Snyder does.
I appreciate the stuff Marvel films are doing with their properties because Jessica Jones, Power Man, Daredevil, and Shield could appear in the Marvel films, and I love that. Dark themes are fine but I don't want it in every movie; the good producers knows how to mix it up. Batman can be handled any way as long as the character is true. Superman should never be handled in a dark fashion, the character is uplifting and any director who doesn't understand that shouldn't be filming Superman.
I think Zack Snyder was the wrong choice for the DC cinematic Universe films, I doubt the BvS metropolis subplot with Batman was by design. It was spawned because of the high level of disgust from viewers having Superman allow such building destruction and not be concerned for human lives, and making Superman kill Zod was another strike against the director.
I hope Ben Affleck, a better filmmaker than Snyder, starts his Batman film and directs a film which start an appropriate DC universe set of films which could lead a JL movie right IMO.