I am just thinking…there is Gotham Knights and Suicide Squad: Kill the Justice League. But where would Gotham Knights go in its sequel (assuming it is successful enough to warrant one)? It may be kind of a “lonely” experience for the game developers to have their videogame be in a permanently separate space from the Arkhamverse games.
I think the Suicide Squad will not just function as a Suicide Squad game/quasi-Arkham Knight sequel, but is also a pilot test for bringing the non-Batman Justice League members to a (serious) videogame. For example, Superman would be a challenging character to have an entire videogame devoted to (one hit knock-outs for all minor bad guys and many major villains). However, I can see Flash have his own videogame. And The Flash has enough of a rogues gallery to have his own videogame followed by a bridge between Gotham Knights and the Suicide Squad game.
I just don’t know what other games could be included in a DC videogame multiverse, since many of other DC video games are based on cartoons, movie, and LEGO (not that that’s a bad thing, it would just make a crossover silly). I guess there can be a multiverse with the Injustice games, Mortal Kombat Vs. DC universe, and DC Universe Online.