I can easily imagine a batch job on a mainframe that sends every hour some important data by mail and that some logic apps checks that mailbox to propagate the data but now that mails have been delayed +12hours it's going haywire
And in 2023, which was more similar to this. This is a departure stop, planes in the air are still heading towards their destinations. This is not the same as 9/11 where flights were redirected to their nearest airports for immediate landings.
It's radio. Either you jam it or it works. That's the selling point.
Has this ever happened?
Happened in 2023 https://www.faa.gov/newsroom/faa-notam-statement
https://www.cnbc.com/2023/01/11/faa-orders-airlines-to-pause...
https://en.wikipedia.org/wiki/2023_FAA_system_outage