So with that little mark who brought the coating/emblem to the game is credited, I have reason to believe in the long run 343i will be allowing player made emblem and coatings. Tho I also suspect they will be tradeable, they do this kind of thing a lot over on Steam games already.
I would have included a screenshot but I am not allowed to add them on my posts. ¯_(ツ)_/¯