I think that this is most likely for a cosmetic store, but the main problem is that we do not know how the store works at all.
What variety of cosmetic objects are there?
Are customization items locked by class and/or faction?
Can you purchase cosmetics with in-game currency that can be earned through playing multiplayer?
Are cosmetics tied to the leveling system that we've seen in the beta?
Can you purchase cosmetics or in-game currency with real-world currency?
Will this ever include non-cosmetic items?
Can this be used to create a Warband-like class customization/creation system that can possibly be used by modders, custom server hosts, and/or certain game modes since the skin customization apparently utilizes a slot system similar to warband's class system?
Can player-made skins be included within this store and also visible to other players?
Will any objects sold in the store have a noticeable effect on the gameplay?
Will there be an option to turn off the ability to see another player's skins, especially if they're player-made, to preserve immersion?
I imagine Taleworlds themselves are pulling a Monster Hunter World and trying to include cosmetics to increase their long-term profits from the game, and are hopefully in the midst of figuring out how they want to pull off an in-game store without being obtrusive or greedy like how Monster Hunter World did it. I much prefer that we don't assume that Taleworlds has had this planned out for months or years and just didn't tell us in a cowardly effort to delay or avoid the inevitable backlash, or even worse, cash in on pre-orders and launch buys, but game companies are known to do even dumber **** (like ban a pro player for a political belief, flat out tell their fanbase not to buy their game, or withhold bugfixes to be sold later inside of DLC packs) so I wouldn't be surprised. I think that if properly handled, a store could add a lot to the multiplayer of this game, but it can also easily turn into a disaster.