They better have a damn good explanation for sure... Because it seemed quite clear that present day Diana, both in her movie, in JL and to an extend in BvS has not seen Steve, the real Steve, since WWI... I mean she's been hunting the only memorabilia of their adventure together for years, until Bruce steals it from Luthor and finally gives it to her in the beginning of WW.
If Steve was alive for real in the 80s, none of this makes sense anymore !
If Steve was alive for real in the 80s, none of this makes sense anymore !