I'm not sure if round-robin is a good fit. As used in tournaments, it simply means that each participant plays against every other participant in turn. It might repeat a couple of times but it doesn't go on ad infinitum.
As used in computer science, round-robin does not reflect how Olympics host nations or cities are scheduled -- some nations/cities have hosted the Olympics more than once, and many have never hosted them.
A better example might be the Presidency of the European Union, which rotates amongst the member states according to a very specific formula:
The presidency of the Council of the European Union, also known as the
presidency of the European Union (EU), is taken in turn by each of the
28 countries of the European Union, according to a rotation system for
a predetermined period of six months. The order of rotation is
determined unanimously by the Council of the EU, based on the
principle of alternating between "major" and "minor" member states.
The presidency change takes place on January 1st and July 1st each
The best word to describe that is rotation -- so the answer was in your question :-)