Where are the options held? With the player or with the team? Are we certain Mikey is still considered a GA?
I have no idea, but it's not listed that he "graduated" Here's the article I found to explain it with a few choice quotes taken out for you.
http://ussoccerplayers.com/2010/01/mccabe-explains-generation-adidas.html
If a player gets a GA contract, is he more or less “in” MLS for four years regardless of his performance?
No. Sometimes after two or three years they’re let go – but it really does depend on whether they’ve been given a real chance and have had a chance to succeed on a team. In some places, players just don’t get an opportunity, so they may have to be traded to give them another chance to play. MLS wants to ensure that players have an opportunity. Mistakes are made, however, and sometimes it is in the player’s best interest to seek employment outside the league.
If it’s a four-year contract, how can it be rescinded within four years?
It’s not necessarily a four-year contract. In some cases, players may sign a four-year contract but it’s often two guaranteed years plus two option years. Or, it’s three guaranteed years plus two option years, so it may turn out to be five-year deal. Each contract is different and there is no set contract for each player.
Who determines when they graduate?
Usually the player himself will determine that, based on how much he plays. If he turns into a regular starter by the end of his first year, more than likely he’s going to graduate. In some cases he may not, but once you’re established in your team, then you’re more than likely going to graduate.
Contractually and financially, what exactly does that mean – to graduate?
It means that you’re applying to the team’s salary cap and the team’s senior roster numbers. You no longer have protected status.