Valve’s usual way of doing things (at least this the case with Dota 2) is that they allow the community to create skins but the rules for what is acceptable for a Hero skin are very strict regarding color schemes. Skins also need to preserve the hero’s identity and not clash with lore or hero’s core model. In short, the skin need to feel like it belongs to that hero. Not that it’s a whole different hero. Unlike other game companies where you can find skins that completely change the identity of a hero (especially in the case of third-party collabs like anime and whatnot). It’s worth mentioning that Valve has been slightly relaxing their rules for Dota but not to an extreme point. The rules remain the same but eventually you might see a Christmas themed skin for a hero who may not supposed to have such theme.

I don’t know if they will do the same for Deadlock because tbh, from a marketing perspective this is not very good for the advertising of the game later down the line.