Cottonwood
Roadster#433, Model S#S37
If the pin just represents the Dedham supercharger poorly located on the map that is one thing, but if as most believe it is new supercharger location located near the NH/Maine/Mass border (i.e. Salsbury) then the mystery will continue until the map is corrected by Tesla with two pins.
Tesla has rarely put pins in, in advance for Service Centers with Superchargers, and only after the fact for some. I put high confidence in that grey pin NE of Boston becoming a Supercharger in Salisbury in the coming months.