It's just the same advice as ever: be extremely, exceedingly careful in what you expose to any network. When I set up machines for production, they don't respond to pings and they don't even have an SSH port open without knocking. There are also ways to eschew the need for an SSH port entirely.

People who never took that seriously will never take this seriously either, and that's their loss. (And loss of the commons, unfortunately.)

There's just also new advice: you can't afford to expose an unsecured system to the internet even for a moment. Think of those IPv4 address space scanners, except this time any one of them could be capable of developing individualized attacks in mere minutes. They don't sleep, they don't take breaks.