I think they would reset the ranks on people that have done this glitch. Not to rank 1, but they will probably look at the experience earned online, and adjust accordingly (if you check the stats of most people that have done this, they are way below the limit required to be level 43 for instance). I've performed this glitch, not intentionally, and I'm currently rank 43. But my experience level is way, WAY below the required amount to be that level.
What they really need to do, urgently, is release a buttload of new maps. There were 6 multiplayer maps in the game excluding the Survivor + LE maps. This simply isn't enough to keep peoples interest peaked. It's why I stopped playing.