Well, yeah, Maz mentions that he is a supporter of the Resistance in the holo scene. And Canto Bight is mostly a neutral zone, since they provide arms to both the Resistance and First Order.

And he’s supposed to be in retirement, too. My TROS novel just says that he was staying out of things after his daughter was taken, and he doesn’t want to kill stormtroopers anymore as a result. I guess the problem is that none of this would be explained until TROS, and until DJ reveals that they supply the Resistance as well he might come off as a First Order supporter.

I think I should just go back to the Maz scene and give him a reason to be there like you said lol.