Hmm. "On 8 April 1941, the United States occupied Greenland to defend it against a possible invasion by Germany."[1] So, first, there never were any German occupiers to liberate Greenland from, and second, the US occupation of Greenland started 4 years before 1945.
> Furthermore, there were emplacements for massive guns with 42 kilometre range, which could close the strait south of the island to the coast of what is now Poland (then Germany).
First, the strait is 90 kilometres wide.[2] Second, the last German stronghold on the southern coast of the strait, the port of Kolberg (Kołobrzeg) fell to the Polish People's Army on March 18.[3] Calling the coast "then Germany" in May is pretty weird.
[1] https://en.wikipedia.org/wiki/Greenland#Treaty_of_Kiel_to_Wo...