When you call you will be speaking with a dining reservation CM who will probably read the warning that any reservation at or after 7:00 requires party tickets. The warning is posted on the online dining reservation page or usually read by the CM if you make the res on the phone. Others have said that they received a phone call if there were no party tickets in the
MDE and the dinner reservation cancelled. Even if the phone CM says you should be fine, you cannot depend on them because they have little experience with restaurant policies. Only the CMs at the restaurant that night can decide whether they will sprinkle pixie dust and let you stay.
It is better to keep looking for a reservation earlier than 7:00 so that you will have no problem keeping the res.