We do not expose our hash based on the Eileen's July 15 EOD email, so in order to handle situation when civiproxy down (civi in maintenance) we show the default simple unsubscribe page without check hash, and allow the unsubscribe request send to queue.
since we will double check checksum in queue consume, so still make sure the request is come from an auth donor.

p.s. we have this patch to remove timestamp for checksum when consume queue, should cover the time during civi maintenance https://gerrit.wikimedia.org/r/c/wikimedia/fundraising/crm/+/1167965