It's not so simple. Before the indigenous Inuits migrated to Greenland there were other people groups there. There were the Dorosets and some people even believe the Norse arrived in Greenland a quite a few decades before the Inuit settled. So the Inuit were by no means the first people to use the land they currently occupy, yet nobody will dispute their claims of being indigenous to their lands.
Contrast this also to the Faeroe Islands (another Danish colony in the North Atlantic) whose current people group settled there centuries before the Inuit settled Greenland, were (arguably[1]) the first people there. You’d definitely raise an eyebrow if you’d hear them being called indigenous.
In short. Being the first people group to use the land is neither necessary nor sufficient for being indigenous.
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1: The islands might have been settled earlier by Irish monks, however (unlike the modern Norse settlers) they never established settlements that lasted for generations.
Contrast this also to the Faeroe Islands (another Danish colony in the North Atlantic) whose current people group settled there centuries before the Inuit settled Greenland, were (arguably[1]) the first people there. You’d definitely raise an eyebrow if you’d hear them being called indigenous.
In short. Being the first people group to use the land is neither necessary nor sufficient for being indigenous.
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1: The islands might have been settled earlier by Irish monks, however (unlike the modern Norse settlers) they never established settlements that lasted for generations.