Note that this list is list of places where if you are enterprise starlink customer SpaceX can provide you with physical ethernet port to plug your cable into when you want to handle your traffic yourself instead of that just going directly to the internet. That is kind of obscure service that even land-based PLMN operators offer but usually do not document in this way in publicly available documentation.

From the perspective of network design, the fact that this certainly is not exhaustive list of places where SpaceX has physical DC presence and physical reality it comes that some of these datacenters are selected based on the fact that the ground station is somewhere nearby (I would be surprised if there is even just one place on the list where nearby means "on the roof", because there is a lot of technical, logistical and administrative reasons why you do not want to put such a thing at a roof of a datacenter).