There has never been anything that made me suspect this. Snyder's creative choices were his own.
WB didn't gave up on Superman (yet), there were talks with James Gunn and, recently, J.J. Abrams to do a Superman movie. CW is "taking advantage" of the lack of a SM movie in development to produce their own show about the character. I think the project will be probably shot down if a SM movie enter in development stage.
Speaking of KC... HBO used a
KC poster as teaser for the Strange Adventures series.