Asked if other family members might be on the show, the network says it is "entirely possible" that while doing the show, the brothers will cross paths with other family members. But A-and-E says, it's too early to know which, if any, other Jackson will be in the series. You can be sure that whatever happens, Jackson's mother, Katherine, will have something to say about all of that. She is the children's guardian - and presumably would make the call on whether her grandchildren from Michael will appear.
The series is to be launched in December.