Until the box saying “Early arrival is most important” comes back (it’s on the page where you put your requests - that page that doesn’t really work anymore on MDE), they should not make an arrival time indicative of anything.
IF your room is assigned and doesn’t meet what you want, you can always go to the front desk and ask if there is another room and let them know you’re willing to wait.
BUT there simply may not be anything that meets all your requests available during your stay period. It happens sometimes. That’s why I make it clear when I set up my fax what my priorities are. For example, my February visit, I said something like:
“I would like to make the following requests in this order or priority:
1 - Surf’s Up section
2 - Top floor
3 - Corner Room”
I put my time of arrival (around 8:30am) but did not check the “early arrival is most important” (that was working at the time). My room was not ready exactly when I got there, but I got the first 2 requests and 2 doors down from the corner.
If you’re really worried about it, either don’t put your arrival time (a moot point if you’re using DME since they’ll know) OR in your touring plans fax, make your closing sentence something like “We are willing to wait for a room to meet as much of our request as possible.”