I came here wondering the same thing as I've encountered a handful of availability issues this morning.
* Todoist MacOS app is having trouble talking to its API
Yes, I'm wondering that also.
Todoist was having issues and iOS app launching from Xcode started taking a lot of time in the middle of the day (which reminds me of the app online check fiasco not so long ago).
Even HN seems to be a bit slower.
* iMessage was taking its sweet time sending a few texts this morning.
* I had momentary trouble trying to call a business from my Verizon phone, and someone I know had trouble calling from AT&T.
Could just be a coincidence, but I wonder if something larger-scale is happening.