The level of trauma is HUGE. The idea that it's over because they're safe in a British house, is naive, but understandably so.
Everybody is on their phones getting updated minute by minute what's happening back home. And none of it is good. It's a prolongation of the trauma or secondary trauma (I'm not sure there's actually a categorisation for it as the West hasn't been touched by this before).
Furthermore, refugees go through multiple stages of loss. It's deeply traumatic to leave everything behind at short notice. They've lost their homes, jobs, daily routines, and are in a different culture, different language, different political, social, educational, health etc systems. They've lost their incomes, their status.
They've lost everything basically.
And the likely have friends and/or family still there fighting or struck.
And then on top of that, they're going to be guests in strangers houses.
Have you ever read threads here about guests outstaying their welcome after a long weekend, because OP wants her kitchen/TV/home back? We all need our space. And that goes for refugees too.
Someone upthread said it's easier than taking in a traumatised foster kid, because at least Ukrainians had normal lives until a few weeks ago. This is a massive underestimation of what it means to be a refugee. It's a wonderfully warm-hearted thing to do. But the understanding of the situation support is woefully inadequate. And that responsibility lies with the government. I'm not in any way blaming people who want to take in Ukrainians. Unless you've experienced or studied this area, you cannot be expected to know.
And I'm not even going to start about safeguarding..anyway, what's to say, cos there basically is none.