As you may already know, the Teenage Mutant Ninja Turtles are coming to Injustice 2. However, while the Turtles themselves are not yet in the game, it seems that their voice lines are.
The voice lines for the Turtles have been datamined in the PC version of the game. 1442Guiman has put together a video with all the voices for the gang, and you can check it out below.
Interestingly enough, the original datamine was for the Portuguese language version of the game. As such, a similar video exists for that version: