I don't think it's fair to expect the EU to bend over backwards to accommodate the defectors after how they behaved. The UK knew what would happen and they choose that path anyway throwing a large number of UK citizens under the bus. It's unfortunate that they made that choice, but it's not the fault of the EU and it's not the EU's responsibility.

It also seems a bit unfair to suggest that .eu domains aren't dependable as if the same thing could happen without warning to any member country considering that the precedent established is that it would only happen to countries that insist on it happening to them.