No, they simply take away your rights to publish your creation to their index.
You can always publish your creation on your website or wherever.
You can always publish your creation on your website or wherever.
What you're suggesting wouldn't solve the problem for critical packages, though; the effect would be similar to yesterday's package unpublish issue[1] (all users of the package would have to update their dependency references despite no change in the content of the code).
The suggestion regarding separation of (immutable) packages and policy in the article could provide some hints in that direction.
After that, if people want to at some point update to a newer version of the package, yes, they will have to adjust.