> Hosting company can not "give" the domain to anybody.

> Gitlab used to be like this

That's what I'm saying. Hosters can "give" a domain (i.e. control of that domain's records on their nameserver only) to someone else, because they're not registrars and aren't _required_ by some painful business contract with ICANN to have to take change of ownership seriously.

They should require a domain validation challenge to add a new domain, like your Gitlab example, but it doesn't seem like anyone can make them.

So therefore the onus is currently on the domain owner not to leave their domains' NS records pointing at nameservers they don't control!