Capcom Cites "Technical reasons"
An intrepid data miner has uncovered what appears to be some previously-unannounced DLC on Resident Evil 6's disc, including a new difficulty level.
Modder Fluffyquack found the content while trawling through Resident Evil 6's code, and posted footage to Youtube. By the looks of things, it comprises a "No Hope Left" difficulty setting, extra character taunts and some costumes. Here's a spoilery sample:
Capcom told Eurogamer that only one piece of DLC is based on retail disc data, whereas others will be entirely new.
"We still have unannounced DLC for RE6 that will be revealed in the coming months and while virtually all such content will not be on the disc there will be one piece of content, that for technical reasons, requires the use of a combination of newly downloaded data and data that is included on the retail game disc."
To be honest, Resident Evil 6 is probably big enough to manage without even more content for the time being, but we absolutely hate on-disc DLC on point of principle. Let us know if this puts your back up.