It is indeed very interesting to see that Greenland decided to go with permanent savings rather than permanent standard. Neighboring Iceland has been on permanent savings for over half a century and there have been heavy discussions around the public health issues that creates (particularly around sleep deprived teenagers). I’m sure the Naalakkersuisut is aware of this but still decided to go with permanent savings.
This article does mention that this brings closer to timezones in Europe (Ittoqqortoormiit which observes its own timezone will then be on the same timezone as Iceland), so perhaps that weight heavily on the decision.