I'm happy to see that the Outback update will include another map-themed outfit. I'd love to see more, including for existing maps.
The attached image includes a few examples that I think would work very well: a buckskin mountain man outfit for SRP, a cool-weather park ranger outfit for Yukon, and a modern but traditionally-inspired European hunting outfit for Hirschfelden. I like to use the caplock on SRP and that outfit would complete the frontier feeling; the park ranger outfit would fit the story of Yukon while also feeling at home in other reserves like SRP and NEM; and the Hirschfelden outfit would be a nice alternative to the camo outfits that feel more American-inpsired.
A cosmetic DLC that included those three would be an instant buy for me, and I'd also be very interested in themed outfits for the other maps as well (e.g. something cowboy/vaquero-inspired for Rancho). If you were feeling so generous as to make them free additions it could be fun to link them to goals within the game, like completing the main story arc for Yukon, completing a certain number of Sommer side missions on Hirsch, or harvesting a certain number of gold animals with the longbow on SRP. (As a side note, another free update that expanded face options and even included the ability swap hair styles and facial hair would be much appreciated.)