That's the "commit-confirm" process they mention they will use in the write-up:

> Primarily, we will be concentrating on automation improvements ... and provide an automated “commit-confirm” rollback.

That's what is suggested in the blogpost as one of future prevention plans.

There was a common pattern in use back in the day when I managed openbsd filewalls (can't remember if it was ipf or pf days). When changing firewall rules over ssh, you'd use a command line like:

$ apply new rules; sleep 10; apply original rules

If your ssh access was still working and various sites were still up during that 10sec you were probably good to go - or at least you hadn't shut yourself out.

Back when I was a briefly a network engineer at the start of my career, on cisco equipment we'd do 'reload in 5' before big changes - so it'd auto restart after 5 minutes unless cancelled.

I'm sure there were and are better ways of doing it, but it was simple enough and worked for us.