Trades made after a player is a free agent no longer affect willingness to sign
You make some trades, clear some cap space, and then when you get to free agency, there he is! The savior of your franchise, willing to sign for $45M/year.
But you only cleared $40M in cap space! No big deal. One more trade to clear up the extra room and then... wait, now he's not willing to sign anymore? His mood decreased because he's "worried he'll be traded away"?
Until today's update, that was a really annoying thing that would sometimes happen. But not anymore!
Player mood depends on how many trades you have made. My thinking was that in real life a player would be legitimately wary of signing with a team that made a ridiculous number of trades, and also that it stops people from making a completely unrealistic amount of trades (like in real life there isn't even enough time in the day to make 1000 trades, but in BBGM you have all the time you want).
I think generally this works well. The exception is when you have a guy who is willing to sign, you make a trade to clear some space to sign him, and then he's no longer willing to sign. That is really frustrating when it happens! Also unrealistic. In real life, you would know a free agent's requirements, and if it was "don't trade this guy away" then you would simply choose between making the trade or signing the free agent. But BBGM didn't give you that choice.
The latest update solves this in what I think is the simplest way. The "number of trades" counter used for calculating player mood is saved for each player at the time they become a free agent. So after a player is a free agent, you can make any number of trades without worrying that he will refuse to sign with you.