Mordru is just being reintroduced in the LSH reboot. Universo and Time Trapper have not been reintorduced yet so they're unlikely. Phantom Stranger and Destiny maybe be trapped in the Vertigoverse which may make them unavailable. Dr. Fate isn't around any more. Brainwave and Ultra-Humanite are JSA villains so DC will deny they ever existed. Shazam will probably wind up being an Ally if he's used. Same with the Chief.