I personally do no buy the "new anodize" process for the USMC. Hard anodizing is a MIL-A-8625, type III, class 2, finish which has been used on M16 receivers for many years. This is a problem with the dye process and/or the anodizing not being as thick as necessary to dye properly, or the post dye sealing process. They don't want to be having to redo a bunch of receivers so they make up some story.
They may have changed from type I or II to type III hard anodizing and probably have not got the process dialed in properly to produce the jet black finish. Also if they were doing a new process for the USMC then they most likely would not be doing it for all the receivers, only the USMC contract receivers.
Someone should find out exactly what the USMC is specifying for the new finish.