So I found a way to injure people for Universe purposes in case you need a reason to keep them off shows and such or maybe provoke a certain Universe Moment.
Customize a match on a major show into a Singles Match featuring the wrestler you want to injure, and another wrestler good enough to whoop they ass. Make sure to put the wrestler you want to injure FIRST, and yourself as the second wrestler.
Get in the match, and during the first wrestler's entrance, do a Run-In. Once you come in, beat on the wrestler until you get the cutscene with the referee breaking up the fight. Don't exit the match, simply press "Next Match".
Once you're into the next match, quit and return to the Universe Menu.Once you get there you should see a brand new News Report for a Minor Injury suffered by the wrestler.
Repeat this process two more times until the wrestler is critically injured. You can do it three times in on one show to have the wrestler critically injured. The injury only seems to be for the head.
Like in 2K15, once they're healed up they'll return during a match and whatnot.