I'm leaning towards it developing like this for the 31 slots on the website, based off 3 things.
1.) Cheetah/Catwoman and Freeze/Cold really aren't that similar. Freeze is a technological tank, Cold is a scoundrel, Catwoman is a graceful thief, Cheetah is a savage.
2.)
http://www.gameinformer.com/b/news/...after-midway.aspx?PostPageIndex=2&PageIndex=2
3.) The mobile game leaker did not know about Darkseid, so presumably he could be in the dark about other characters from the console version. I guess just 1 more -- Luthor-- but hey Freeze and Cheetah could be costumes and there could be 3 missing.