And those DQ's would play on other teams. I think some of you are overblowing the impact.
Sure, but the problem of re-sorting players remains.
There is a perceived hierarchy of teams, from blue bloods all the way down to Rutgers. In general, players get to sort themselves once now, on signing day. Blue chips flock to the blue bloods. Parity comes about only through player development at the lower-tier schools, or through more diligent research and prospect identification (diamonds in the rough).
Added mobility after signing day is going to reshuffle players, and the upward pull on kids who are proving themselves to be blue bloods will be relentless. Alabama DQ's someone, and pulls a kid up from South Florida. In general, that DQ'd kid is not going to end up at another tier-1 blue blood, he'll end up further down the hierarchy. The net effect is a transfer of talent upward. On average, the "trade" will benefit those higher in the hierarchy.
A competing dynamic will be blue chips who want to transfer out of the blue bloods to get playing time. That could offset the re-sorting effect somewhat, but the possibility of a lateral transfer there is real.
There is also the problem of roster maintenance if you are bringing in too many short-term guys. It would be like trying to manage the roster with too many JUCO's. Maybe that will keep things from getting too far out of hand.
Simple analysis, but I foresee the greatest headaches where the big money is involved.