Don't forget, it's a competition. Some consider it to be the Superbowl of comps. I think people should do whatever they can ( outside of cheating ) to present their best beer. If that means rebrewing, not rebrewing, etc, so be it.
I don't think holding scoresheets would matter too much. Some will rebrew even before they know they advanced. Maybe they tweek the recipe based on comments from other competitions. I got my scoresheets back a month before the official release of the results ( I sent to the Philly region ), but none of them were marked with a place awarded. I figured they didn't make it through. Then the results came out and I got a second in the Light Lager category ( thankfully I didn't drink it all yet ). Maybe the AHA can have the regions not mark a place awarded on the sheet, that way everyone knows at the same time.
As long as everyone has the same opportunity, then bring it on. My entry going forward is a Munich Helles. I'm not rebrewing it, mostly because I'm lazy, but also I just don't have the time. If it doesn't win in the second round, that's ok.
I think the AHA and all the volunteers are doing a great job running the largest homebrew competition in the world.