As of right now according to the Xbox marketplace, the season pass is "Not Available" on Xbox 360. Of course thinking Activision won't want to suck dry all the COD fans out there is another story. Most likely they will still be able to get every map pack released for Black Ops 3, just not at the cheaper price a season piss would offer.

Side note: no word on the PS3 having this situation as well. Call of Duty is siding with PlayStation this gen so it could very well still offer it on that console. We will try to find out if this is the case and report back.