We did have an whole Enforcer set. Similar but not the same, yes.
I think we’ve kinda gotten several non-Catachan Jungle-Fighter-lite sets. Not with the signature sleeveless uniforms but jungle/swamp-themed all the same.
I thought we got a Valhallan set? We got ushanka style hats, at least, and one even mentions Valhalla in the description.
Edit: also found this:
And this Valhallan-lite great coat:
And I remember a flier for a full Tallarn set was one of the first cosmetic things data-mined from the game way back around launch, but wierdly, it never showed that I recall. Following the trend, we did get a bunch of generic desert garb. So, yet again, Tallarn-lite.
Nothing approaching Atillan, sadly, and a great many other of the best known and liked regiments of renown from across the Imperium.
Apart from the kinda-Valhallan one, the regiments from the wider lore that I know we have gotten have been Tempestus Scions, Kasrkins , Cadian Shock Troops, Death Korps of Krieg, Armageddon Steel Legion, Elysian Drop Troops, and Savlar Chem Dogs. So with all those, it’s strange they are hesitant to do more. Maybe they are trying to spread them over more time? But then why re-do the Steel Legion and Death Korps when there are oodles you haven’t gotten to?
And agreed, they do need to just open up the back-catalog for purchase. Have the new stuff sold at a “discount” if you NEED to keep some minor urgency element in, and then mark it up when it moves from the “new” page to the catalog. Sea of Thieves did all that and it seemed to not only work just fine but to be fairly optimal as far as cosmetic stores go.