Not the case, I monitor this (automated - using the old gravity database to calculate 'new blocked' and 'new allowed' / compare with my actual queries, used code here). This week, only one domain that was accessible (and used) before the weekly gravity update is now blocked (collector.github.com). Also, windows update would have failed, since redirection (to pihole) is in place, everything is always resolved by pihole.
Just guessing here:
could have been a temporary DNS resolution problem, it (redirection) didn't happen today (windows update is triggered every 22 hours). Recently, I see more unbound problems reported, latest I've seen (reddit) here, on this forum here.
I just need to improve on alerting.