This game is clearly Overwatch. It would be something different if it was just "Oh they have rockets, that's Pharah, it's Overwatch". In fact that rockets are the least comparable to Overwatch of all I really saw just now.
The main thing that I can discern that is different is that this Lawbreakers game doesn't have identifiable characters, especially since each character can carry all the weapons. I don't know if that's definitely the case, but that's what the video demonstrates. I wasn't listening to it though so maybe the guy said something different.
Mortal Kombat wasn't just a gritty skin placed on top of Street Fighter. It wasn't just a mature fighter. It also wasn't "just" mechanically different. It had a lot of differences going for it, so much that the only similarity was that they were 2D fighters. The best comparison you could make to this is that Lawbreakers' characters have the same basic core moves, just as how MK characters do, but that wasn't exactly a positive thing about MK.