I'm not a huge fan of Substack, but this seems like the most cynical interpretation of what Substack is. And the whole point is just to police the words people use to refer to their blog?
If you call what you have a Substack and then you move it, what do you have, and will people think you disappeared when you just are self-hosting or moving to Ghost, Buttondown, Beehiiv or someone else?
I guess we got over it.
The existence of the special term has caused a good amount of harm by enabling this confusion.