This seems to me a bit academic given a 10 min as opposed to 5 min MCT limit is available as a service bulletin with I believe no technical changes.
I guess you made a typo, it should say TOGA instead of MCT, but otherwise spot on. All 737 engines are certified for 10 minutes takeoff thrust (only in case of engine failure of course), as long as you pay the hefty fee to Boeing, who will then provide you with the modified AFM and relevant performance data. Absolutely no maintenance action required to switch from 5 to 10 min.
Too bad many pilots don't know this and think engine falls off the pylon after using TOGA for 5 min and 1 second.