Ok, maybe a little early, but screw it. We had an official Gambit thread while it was stuck in limbo, so...
The news as of now is Mangold is drafting the script alongside X-23 co-creator Craig Kyle. As of yet it hasn't been officially announced for production by Fox, but we do have confirmationthat there's active development ongoing. Dafne Keen is almost certain to reprise her role as Laura, but the story and potential rest of the cast is up in the air.
Personally, I think a loose adaptation of Target X, with Laura being sent to ground with a Canadian foster family by the X23 kids' unidentified benefactors would be the ideal focus. Maybe they decide that the best way to protect the kids his to separate and hide them, rather than keep them all together where they'd be more conspicuous. Use Megan and Debbie (Megan should totally be played by Milly Bobbie Brown) as the family who accepts her. Think coming of age story with a violent twist as Laura learns what it is to be a normal kid while what's left of Transigen tries to hunt her down.