I'm with those who question the legitimacy of Avery switching agents so that must mean he was unhappy with his contract.
Here's the thing, Avery Bradley agreed to his new contract on 7/2/2014. The new TV deal wasn't announced until 10/6/2014, and doesn't even go into effect until next season.
There was no way to predict when the tv deal would be signed, how much it could be for, and how it would effect the salary cap. Silver actually wanted to slowly increase the cap over several years (while still giving the extra money to the players) instead of the large, sudden increase we're going to see next year. Had Silver gotten his way this is likely a non-issue.
I'm sure everybody who signed contracts 2014 and earlier is unhappy with their luck of the draw (
like when we saw John Wall say this summer how Reggie Jackson got the same contract as him). Kind of like I'm sure all the players who signed contracts pre-1996 when the cap first exploded are unhappy they played in the wrong era too.
It's like deciding to sell your company stock that for the last 10 years only gave 1% returns per year on average (which is what the NBA salary cap rose at when adjusted for inflation from '05 to '14), and then 2 years later it spikes up and increases 70% from when you sold it. Man, your kicking yourself and can't help but think "what if". While you're unhappy with that move, you're still pretty happy overall, and you know that's just one of those things you can't really ever predict.