The article 100 definition of Readily Accessible says "Capable of being reached quickly for operation, renewal, or inspections without requiring those to whom ready access is requisite to take actions such as to use tools (other than keys), to climb over or under, to remove obstacles, or to resort to portable ladders, and so forth."
Notice that the word "remove" was chosen for the definition and not the more broadly applicable word "move". To remove the microwave from the countertop would be to take it off and place it somewhere else. If the microwave can be shifted to allow access to the receptacle and still remain on the counter then it has not been removed.
Also, it sounds very likely that the GFCI receptacle is more "Capable of being reached quickly", reset, and put in operation in much less time than going to a breaker in a panel to do so.