I'm thinking he “came out” when he did in an attempt to use this issue as leverage to guarantee a spot in the NFL. He's setting up his “ if you don't draft me your discriminating against me because I'm a homo” defiance.
defiance = defense
Isn't there a picture of him in a gay bar stripped to the waist partying? Maybe he made this announcement to check-mate the impact of that photo. Otherwise, why not just go through the draft and answer any questions discretely and honestly about his sexual preferences, when and if they came up?
I'm sure I encounter people every day who are gay. My attitude is I won't bother you with stories about my sexual preferences, please don't burden me with yours.