Ornithopter is a type of vehicle. It's unlikely any specific vehicle of the type would be generic enough to operate across the variety of planets that likely exist within the Imperium without modification to the design.
This particular branch of the discussion was focusing specifically on the feasibility of the 'dragonfly' ornithopters operating on Arrakis as represented in the new film.
To be used on many different imperium planets seem to imply that it operates across an acceptable range of gravities and pressures, etc.