That possibility had not occurred to me (in my mind MSU doesn't seem like a "ferret out the roid-users" type of place), but upon reflection your suggestion seems credible.
"I've talked to all the NFL teams. They know what happened and the situation. Moving forward is not going to affect my draft stock whatsoever."
Also, it's interesting that if it is steroids, and if Bullough really did disclose the issue to all the NFL teams, that Bullough feels that such a disclosure would not trouble those potential employers. A sad commentary on the NFL if the common thinking is that getting busted for roids won't affect your draft stock in a negative fashion.
Second, it's interesting that MSU has at least evolved to the point that they would suspend a player for steroids. (Picture of Tony Mandarich goes here.)
But steroids at MSU? I'm shocked, shocked to find that doping is going on there.