There's no point to doing a sequel to Alien Resurrection, anyway. There's only the crisis of Ripley 8's duality to work with, really. The USM are throwaway, and there's no meat on the bones of any of the other Resurrection survivors, really, except for Call and the Auton units... None of that would really, in my opinion, make for a compelling sequel. Especially going on 21 years later.
Personally, i'd love the series to go the route of Alien Isolation. Something like that, anyway. Pull back from the mythos aspects being explored in the prequels and go back to the mystery and bizarre horror of this universe.
Hell, something along the lines of Alien Isolation, broken into six hour long parts for Netflix. Do an Alien miniseries.
You could do a The Thing-Esque miniseries. Call it, say, "ACHERON"
Story would show the life, struggle, and ultimate downfall of the people of Hadley's Hope to the aliens. Even ending it on a bleak Carpenter-esque note. Newt left alone somewhere in the base, the only other human character is left cradling a gun with one bullet, a fire dying down under sprinkler systems, an old style motion tracker bleeping as the Aliens close in. HARD CUT to DARKNESS.