Game developer NetherRealm Studios might actually be announcing a new Injustice game at the upcoming DC FanDome event with Ed Boon confirmed attending it.
Boon confirmed his attendance on his personal Twitter account and also proud to say that he is on a panel with Dwayn Johnson. Since the upcoming online convention is focused on anything DC, the only logical conclusion everyone could get from this tweet is that he might just announce the next installment to the Injustice series.
It would be impossible for Boon to announce a new Mortal Kombat game since it was just recently that Mortal Kombat 11 got the Aftermath expansion. Also, the event is a DC-focused one, so Mortal Kombat-related stuff is out of the question.
The tweet from Boon is fact, but the assumption of a new installment of Injustice is all speculation. We will have to wait and seen this coming Aug. 22.