I wonder if perhaps “lots of computer things would have gone splat” actually means “management believes that lots of computer things would have gone splat”? It sounds like the sort of thing “we’ve always done” despite no-one testing it since the 1990s.
Maybe, more fairly “techies who’ve worked on the stuff for years have a very strong suspicion that it will go splat” is more accurate, but the effort to test every single element would be enormous, and it’s simpler to err on the side of caution and turn it all off.
They can, for sure, but not all the computer systems we’re using are sophisticated nor were they all programmed in 2024
Indeed, legacy IT is, er, ‘complicated’