A few legitimate use cases could be:
*Superprotection by stewards of legally or technically sensitive pages, to
prevent damage caused by a hijacked admin account. The theory here is that
admin accounts are more numerous than steward accounts, so the liklihood of
a successful admin account hijack may be higher. Superprotection would
proactively limit possible damage. Admins doing routine maintenance work,
or taking actions with community consent, could simply make a request for a
temporary lift of superprotect by a steward or ask a steward to make an
*Upon community request, superprotection of pages by a steward where those
pages are the subject of wheel-warring among local admins.
*Superprotection of a page by a steward for legal reasons at the request of
WMF Legal, for example if a page is the subject of a legal dispute and
normal full protection is inadequate for some compelling reason.
None of this is an endorsement of WMF's first use of superprotect. I would
prefer that if superprotect continues to exist as a tool, that it be in the
hands of the stewards and not WMF directly.