BATMAN..SHAZAM..and BLACK ADAM??? WOW!!

[Vendikarr]

Dont they own these characters outright?

There's a lawsuit going on about the Superman rights. The Siegel family are trying to reclaim some of the rights.

But how would that effect where Superman can be used?

Whenever the character is used it means money for the rights holders. DC may be limiting his exposure to minimize future payouts.