It's good to have an option like that, even being a default, but there definitively need a switch to disable that if it is your own will. It's not even necessarily that good enough against cops, because in a lot of shitty countries, even some pretending to be democratics, not disclosing or at least inputting your password might be a crime severely punished. If I'm not wrong, there was a guy that had to stay years in…
It's good to be able to disable this option: I use old Android phones as servers and don't want them to reboot every 3 days.
Don't think old Androids will get this update.