Author here. This is definitely something some WISPs are worried about. It's likely that Starlink will take a lot of the most rural customers. WISPs can also be very successful in more suburban environments, and can speeds much higher than Starlink can provide in suburbia (300-500mbps) at a lower cost, so there will probably be a place for WISPs at least until there is no gap between fiber availability and Starlink as the best option.
Also, a lot of WISPs have started running fiber in rural areas, so that's another way they can stay relevant.
starlink is in no way a competitor to a modern ISP, on a modern ISP it's normal to have >=1Gbit and more than 10 times less of a latency compared to starlink, and the maximum potential userbase for starlink is a fraction of internet userbase
oh, my bad, i did open the link, but jumped straight to marketing section(since it was my point of interest)
and somehow assumed it was about local small ISP's, with wireless it's not that simple, yes.
But still, it's mind blowing how horrible ISP's in US are, you would think if in some third world countries it's accessible, everyone in US should have it.