Maybe it's for the best. Furisoa was alright, but it did have the distinct feeling of an attempt to start a cinematic universe. It was the first Mad Max movie to be so directly tied with the continuity and canon of the preceding movie. That is a very different feeling than the loosely connected, sort of folk tale feeling the other movies had in relation to each other.
This new Wasteland movie sounds, just by the short description, like it would have been like Furisoa with a tight connection to the other movies. I don't think Mad Max needs to become that.