This is nice, I hope they're open about doing more Big Chap too.
They'll be re-releasing Big Chap, presumably with the upgraded articulation at the very least, but not until 2019 for the 40th anniv. of ALIEN.
Between now and then, we've got:
2017 releases:
Waves 11 (mixed), 12 (ALIENS), and maybe 13 (Kenner), + special releases like 2 packs, dioramas, and exclusives.
2018 releases:
Waves 13 (if not released in '17), 14 (slated to be Resurrection), 15 (recently hinted to contain AvP:R xeno, so will likely also have the predalien, leaving an empty slot for ?), 16 (Kenner), + special releases
As we've seen with ALIENS 30th anniversary, releases haven't been contained exclusively to the anniversary year, so who knows - maybe the Big Chap could sneak its way into the lineup earlier, but I'm not expecting to see a 'new' version until wave 17 in 2019... which could be a good thing if it gives NECA time to give it more than just new articulation. I'd love to see that figure's stupid horse grin replaced by a more sinister expression - hell, maybe they'd even be thoughtful enough to give it an alternate close-mouthed head like they've done with the neomorph.