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 that sort of architecture is normally not a problem (finance has all sorts of stuff like that)... but national ATC systems are not the kind of situation were some SRE can just side load the file while keeping their job.