from the article, ISPs are interested and presumably they will turn the flat pricing into plans. Dropping a solar powered cell tower with Starlink backhaul on top of a mountain could easily serve 200 cell phones paying $2/month each
At that point, the cost of a microwave backhaul, even if you end up needing a few repeaters, is a small percentage of the project cost.
That means even if starlink works out cheaper than the microwave backhaul, you won't see a sudden growth of these kinds of rural transmitters, since the economics for the phone company don't change much.