No clue. As a guess I would say one of the nintendo titles has the record. Wii Sports maybe? Destiny had some pretty jarring numbers as well, but no clue how those stack up Overwatch for new IP launches.
edit: to be fair nowadays there are only like two or three tops AAA new IP's released a year so it's almost a moot point in today's market that favors sequels so heavily over new IP's,
Edited by DNMock - 6/18/16 at 9:15am