I recall seeing or reading about (I can't recall) an interview where one of the Superbot employees (I think it was Omar) talked about how they didn't know how to handle dlc maps. So I want who ever in Superbot is in charge of viewing these posts to pass this one in particular to whom ever is in charge of such protocols.
I think that the only proper way to handle dlc maps would be by having them playable on rank only and bundled with characters.
Here are my reasons:
1.Not having them playable in rank matches would divide the online community.
2.Separating maps as single dlc would most likely detain some, if not many, people from buying it as there would be no incentive of buying it considering number one (i.e. being already capable of playing the map without buying it, albeit only in rank).
3.Being bundled with characters would raise the incentive as many, if not all, would want the characters playable.
Yes, I understand that this would most likely hike up the price of a single dlc (and as mentioned before, some or many of the players would not want to buy the maps), but this option is probably the only one where map dlc is possible from a business and a non-online breaking perspective. (Business perspective has to be considered if people want to see more maps in the future)
Edit: Darn forum posted it as a paragraph