So because someone else was also offering a solution, Starlink is the stunt? Is literally everything in life a stunt if someone has done it before you?
They literally set it up at the one place in town that already had working Internet access and power. On top of the generator of the entity already providing such. Yes, that's a stunt.
I don't doubt they're using it, just that one particular photo was possibly the worst possible choice for PR. Take a photo of one out in a field being powered from portable equipment with a Honda 2000 inverter-generator or something.
The location of Malden works for them because with the current bent pipe satellite architecture, and starlink earth stations in Redmond, North Bend and Brewster, the beta-test CPEs are simultaneously in view of satellites that can also see the earth stations. Activating a temporary CPE in Malden is no different than the same equipment that's been in field beta test with spacex's redmond based employees around WA state for several months now.
And it's at a sufficiently high latitude that the partially-complete satellite network density, at any given point in time, is denser above Malden than above a place several degrees latitude further south.