Not really. They probably just wanted to bring it to an end. If there really was collusion, They could have gotten a lot more than 40ish million.
I disagree.
Correct me if I'm wrong, but we have no idea how much they received, only rumored figures. Even then, 40 million is a very, very large number, and a day one payout with no further work required is an easier grab than potentially getting less, or nothing at all (since it's all up in the air).
The NFL knew they fucked up and paid up to stop it from going public. Simple as that. They would have lost far less letting this go forward, zero possibility this case would have cost them nearly 100 million dollars.