There's no reason to believe other mining wouldn't face the same obstacles as the opposition was in regards to environmental preservation concerns.

No, there is not. There is absolutely no reason to suspect that Greenland would oppose mineral extraction of other resources that aren't nuclear. There is a recent history of both Greenland attempting to partner with anyone who wants to to develop their mining sector (Including the US) to achieve economic independence from Denmark and the US/Denmark covering up Greenlandic citizens getting cancer from US nuclear material. Greenland both have an inflamed relation with nuclear material and a strong desire for an expanded mining sector. They are absolutely open to negotiations with regards to the environment (As indeed they did with the cryolite and the lead/zink mines)