So, has anyone seen this?  Apparently from the Beta Testing/QA for the co-op component, there are many levels, each with a different Assassin/Playable Character. Images show what appear to be Shao Jun, Aveline, Haytham, Rodrigo Borgia(!), etc.
Also videos from the Beta Test are out. 
Keep in mind that the some of people who've come out and shown these have been confirmed as participating in the beta, although there are mixed reports, others, also confirmed, claiming the multiple Assassins thing is false.
So take all this (except the video, video seems to be legit) with a massive amount of sodium.
EDIT: On closer inspection the image may be complete bull, considering it reuses renders from other media. Even Shao Yun seems to be a crop from Embers.
EDIT 2: Haha, even the video is bull apparently? A longer video with the same stuff was uploaded here. Same day even.
EDIT 3: And another leaked video, this one showing a mode that the fake leaker described. Also it seems like it's a map that happens in the Third Crusade?