I have been thinking for some time now of pitching something like this to my university’s Graduate School. We already record our lectures, so technically making it freely available online should not be hard. I also believe that there is a strong case to be made why the course should be “open source” and how that would amplify its impact.
I will post an update if I have something more concrete. Although whether or not I am available to teach said course is to be seen.
Basically, I think a good way to market Fortran would be to go to the Graduate Schools of universities since researchers are some of the main users of the language.