As others have said, this is clickbait.

e: I found this which answered my question. In short: the safest option is to completely turn off the phone.

iPhones in AFU mode […] required physical access and were costly to do

All iPhones have encrypted file systems (as long as it has a passcode, which I think is mandatory now).

iPhones can disable their biometric scanners and require a passcode by pressing the power button five times. Anyone know if this also takes the phone out of AFU mode? AFU mode according to this is when the phone stores its encryption keys in memory.