the most important function of on call rotation is there to fix problems, not to make announcements to the public. so they surely have the first, but maybe not the second.
It’s usually much better ROI to publicly acknowledge an issue if the resolution is not going to be single digit minutes, as it massively reduces the incoming query/support burden
ad agencies? are they going to get upset if their ads are not visible for a few hours on of many sites where they post them? are they even going to notice?