My short answer is that it has a coated piston and a plated bore.
My longer answer is that they wanted less maintenance and lower emissions than other engines. Therefore, they chose a cleaner-burning synthetic oil, specified a lower oil-gas ratio to try to minimize buildup, and relied on the coatings to avoid seizure when lubrication conditions worked well.
In my case at least it worked. I got 81 hours out of a Rotax piston on Gulf 93 and Motul synthetic. It’s probably the best part of the Rotax package.