On the Xbox Live Rewards website, Microsoft has listed release dates for games that have no officially announced release dates. Mass Effect Andromeda is listed for March 31st, South Park: The Fractured But Whole for March 30, and Injustice 2 is set for March 28.
So far only Ed Boon the creative director of NetherRealms Studios has commented on the leaked release dates. On twitter he states that Injustice 2 will not come out on March 28.
FYI: Injustice 2 is not coming out March 28.
— Ed Boon (@noobde) January 3, 2017
There are also some inconsistencies on rewards pages itself. Every confirmed release date given is set a day early such as Resident Evil 7 being listed for Jan 23 when the official date is Jan 24.
It could be that the dates put forth are placeholders for games confirmed for early 2017. There is also the distinct possibility that one or more of these games are pushed out of early 2017. EA has already stated before that they are willing to push back Mass Effect Andromeda if need be. It is best to take these release dates with a grain of salt.