Single Status Update
There are so many detailed rosters of the MTA, but none of retired buses.
There's one on the forums of scrapped buses: http://www.nyctransitforums.com/forums/topic/47568-mta-bus-operations-scrapped-equipment-list/page-1
Unless you mean one with all the retired buses throughout the fleet history. There's one on Wikipedia right here: https://en.wikipedia.org/wiki/Retired_MTA_Regional_Bus_Operations_bus_fleet