It is just as you said. As an example you can look at heapoverflow.ml which got domain high jacked. It is down but the content is still available on other instances:
Lemmy Support
Support / questions about Lemmy.
I didn't know heapoverflow's domain got hijacked, do you perhaps know more ? and if they got a new domain ?
Here the admin did announce it: https://lemmy.ml/post/741881
I do not know what happens with a new domain. It is probably as if it was a brand new instance.
EDIT: maybe @Thann@lemmy.ml can tell you more
yeah, I have a new domain, but all of the internal links point to the old domain, so I have to make a migration to up date the DB, and i recently got laid off from my job, so I put that project on the back burner =/
That's cool! Not that the domain got hijacked, but the fact that the content is still available on other instances. This is brilliant and shows you the benefits of federation VS centralization.
Goes to heaven