I looked into replacing the one on my prior coach. From research, it boils down to the size of the opening in which it is installed. On mine, after removing the face plate the microwave just sat in the opening. There was also about one inch of trim board that could be cut to enlarge the opening for a larger microwave.
I suggest you remove the face plate from the microwave, if one is installed and them measure the opening. You can then go on line or to a store and look at the dimensions of a MW that fits your opening. You may even find a combination MW / convection over that fits the opening.
I did eventually replace mine but it cost me over 100K (new coach).
US Army (Ret)
2020 Entegra Accolade 37TS
2019 Jeep Grand Cherokee Trailhawk (Toad)
FMCA - F432054