You got Eldar, Orks Space Marines and maybe even Nids before IG
I wouldn't hold your breath
Space Marines and Nids have always got an update when a new edition comes out.
You're assuming they do updates based on age or need and not potential sales.
Guard are the #2 sellers these days after different colors of marines, so there might be an IG
update before Orks or Nids.
Catachans were recently made mail order only which might mean something.
Lots of plastic and most finecast kits have gone to mail order. GW
has really been eliminating a lot of stuff from store stock.
The only thing for sure is that Eldar are next. SM
seems likely after that but no hard confirmations yet and beyond thaat it is anyones geuss. I bet IG
gets a new book before Orks and Nids.