User blog comment:Argorrath/Sledgehammer Games claims to be working on a new MW game/@comment-4122733-20130719145010/@comment-1263839-20130720082750

Raven Software made the DLC maps. So that would be the DLC maps and each Face Off map.

But I thought both Sledge and IW worked on both aspects, if not I wonder what justified an entire company's worth of men to make only minor additions to the multiplayer.