The building insurance a landlord holds on their property generally forbids renting to asylum seekers. They would need to pay extra for an endorsement allowing this or potentially move to a specialist insurer.
I have no idea if the visas Ukrainians will receive under this scheme classes them as asylum seekers. I also don't know if a UK renter trying to house a Ukrainian under this scheme would cause insurance problems. It would appear to if a landlord wishes to provide an entire dwelling.
I'm sure it's not as straightforward if you're a renter but if you're keen to do it at least make some enquires before simply writing off the idea.