My husband is in a wheelchair and we have been on many cruises. (Princess, Holland America, Celebrity, Carnival, Fiesta and NCL) Just got back from one through the Panama Canal with NCL. Would not go with them again as they have a new policy that if you are in a wheelchairs and unable to stand they will not take you off the ship when they use a tender and do not dock.
This has never been a problem with any other cruise line. As far as I can tell on this proposed cruise we dock in every port, so should not be a problem. If doing tours from the ship you have to make sure that they are accessible.
Hilari