Keep in mind, another Mauldalorian, Gar Saxon, eventually started to serve the Empire, becoming the Mandalorian governor. Considering that Gideon had the Darksaber, it is reasonable that some of those who followed Maul would also follow Gideon for the same reasons. I am looking forward to hopefully seeing these guys, and their armor, in live action.
Also, given how this show has picked up on pieces of Aftermath, I am curious if the talk of the Pirate Nation is going to lead to followup of apparently one of the Super Star Destroyers being stolen by a pirate.