I know they've recently created an easy way to share new sets of POIs through the TomTom Home program, but I don't think there's a way to directly share map corrections.
It's my understanding that corrections you make to your unit that you share are only submitted to TomTom to review. After that, then it'll release them to be downloaded as corrections. There's also a setting in the MapShare menu that basically sets who you want to get corrections from.
The list says corrections I made myself, verified by TomTom, to POI I subscribed to, from trusted sources, reported by many, and reported by some.
I'd guess that because not many people would report the corrections and changes I did, your unit would have to be set to include "reported by some". I also don't know who/what "trusted sources" are.
If you do the "reported by some", afterward check the turnaround on World Drive that gets you from the MK toll plaza over to the Car Care Center. That and the roads within the CCC should be un-blocked. (Before, routing to the CCC would mean driving up and around past the Poly).
-Rob