Certainaly, sapphire is a more robust material and more modern, but it seems if the other Moonwatches use hesalite, as did the original, this one should've too. Perhaps it was simply a sourcing issue, and Omega could not get its hands on hesalite crystal in this smaller size (the standard professional moonwatch is about 3mm larger than this watch), so they borrowed a normal sapphire crystal from another watch. Not a big deal at all, but worth noting.