Dwayne is expected to play Black Adam, a DC villain, in the future and Henry is Superman for the DC Extended Universe and now they have planted the idea of the two characters crossing paths soon. On both of their Instagram posts had them both saying, "We're excited for what the future brings," coupled with hashtags for their respective characters. One can only assume that they are plotting together to make some DC noise.
A possible thing that they are working together is to have Black Adam show up in the sequel to Man of Steel and be a villain for the Kryptonian son. Another potentiality is the opposite, have Superman show up in Shazam - the film which Dwayne will show up as Black Adam - and be a helping hand for Shazam.
One can only wait to see what the duo is concocting, hopefully we will get a clearer picture as to what it is soon, possible next year's San Diego Comic-Con.
