Here is an example of waiver. Also a good example of a contract of adhesion.
https://www.chicagotribune.com/chi-northern-illinois-nil-waiver-20150326-htmlstory.html
These documents don’t come out at trial because the schools (and other entities that make you sign things like this) know that it won’t hold up. The purpose of these documents aren’t to win at trial.
The real problem that the minor leaguers have is that if they choose to make a stink of it, the video game will just take them out – and most of them like the fact they are in the game. Again, we are making them victims of our imagination.