Deleting of your hub has been an active topic for over a year now so I would not hold out hope for a hub lockdown feature any time soon. Do submit your feature request to ST in the app by tapping on Menu and select Contact us.
It would also be great if ST added the ability to restore from the cloud backup of the hub for a set period if a hub gets accidentally deleted. Currently if you delete a hub… all backups are wiped out with it.