And honestly Emma Frost and Magneto have already started debating whether Krakoa needs to relax the borders to account for human society refugees. They came to a compromise because they didn't think the entire quiet council would accept it while Krakoa is still in the process of building itself internally as a country. So the compromise is that they could extend aid to human refugees and let them live on Island M while they apply for asylum to any country they choose.
It's complex, the other part of this that very few humans would enjoy living on Krakoa. There are no roads, no cars, people constantly using their powers to build things and to fly and to move around. Telepaths talking to everyone. Kyle knew what he was getting into because he had been around other mutants for a long time, so he didn't have trouble adapting to living on Krakoa. But other humans might find Krakoa to be a huge change for them. Plus you have to be a tad careful on the island itself, it does need psychic energy to stay powered.
There is another issue, the resurrection protocols and the slow move to bring everyone from Genosha and the M-Day Decimation back. This is a confidential and internal Krakoan matter. Plus they honestly can't bring humans to life, Charles doesn't have mental backups of humans, and Sinister doesn't bother cataloguing baseline human dna anymore, he can't be bothered. This is why they can't really resurrect humans, they don't have viable backup date of human dna, and the mental backup of a person's identity. Thus they need to keep the resurrection protocols to themselves. Eventually humans are going to know about it and start demanding resurrections for recently dead or long dead relatives, especially if they realize Genosha citizens are suddenly coming back in large numbers.
I could see some human demagogues attacking Krakoa to try and kidnap the Five to enslave them to keep the demagogue and his family alive as rulers for all eternity. There are a lot of modern leaders in several countries who would kill and commit genocide if they thought they could gain the secret of immortality. Even if they had to kill every mutant on Earth to obtain it.
Personally, I feel like Emma is trying to find a way for Krakoa to interact with humans more without jeopardizing the security of the Krakoan island, or their technology. Island M is used as a shipping port that both mutant and human vessels are about to use to exchange goods. The Hellfire Corporation and Frost International ships are not all staffed by mutants, the company is too big for that, so I imagine they have several ships in their fleet that have human captains. The island that Magneto convinced Namor to give to Emma is now a base of operations and it is supervised by a human lighthouse keeper and probably his village. The Hellfire Global building on the island is meant for diplomatic envoys to negotiate between Krakoa and other countries, or CEO's to negotiate business arrangements with Krakoa using the Hellfire Corporation as the liaison.