Whilst I can't profess to have certainty around the legal...

Whilst I can't profess to have certainty around the legal obligations in this situation common sense would suggest that GML's development of a plan over a period exceeding 10 years at a cost of over $130M whilst following all protocols would put them in a strong position to be compensated.
I think common sense is going to have to prevail at some point because whilst the GOG can try and take a hard line stance at the moment their unity is going to crumble once the citizens realise what is at stake.
One question that needs to be asked is what would adequate compensation be. Whilst GML might have spent $130M my personal thoughts are that this doesn't come close to adequately compensating the company for what they lose. The US$640M annual block grant from Denmark seems more closely aligned with the type of revenue GML was expecting so perhaps that is part of why they need to get involved. We can just tell Denmark to pay us the block grant from now on.
Alternatively, if we assume the Uranium legislation is allowed to stand in its current form we would have to assume that the price of land in Greenland is going to drop dramatically as many projects would no longer be viable and the mining community probably avoids investing any more funds there due to the uncertainty. We might end up owning half of Greenland and can start taking summer holidays there in the future.
Once the Greenland people realise this ends up being a high stakes game of absolute poverty or just relative poverty if they win it might not be a game they want to play anymore.
I can't see how Naaja and her cohort could stay living in Greenland if they force the issue to that point. Surely the Greenlandic people would hunt her down with their pitchforks if that is where it went