I think most of it makes sense, CoolGran55.
Firstly, the majority of people inviting Ukranians into their homes are unlikely to be the same ones who were unwilling to have visits from 'positive' relatives. BTW, not all Ukranians are unvaccinated.
Secondly, I know nothing about the process, but it's possible that these refugees are being tested for covid before they are housed here.
Thirdly, the plight of these people who have fled for their life is so dreadful that if you balance that out against out the risk to their sponsors of serious illness or death from the current dominant strain of covid, helping them clearly wins hands down for those willing and able to do it.
That's how I see it, anyway.