User82636 unsure because maybe this has more to do with the old update method? Using A/B seamless updates, maybe this isn't applicable? Or maybe turning this on will actually make the OS ask before it starts applying updates?
The text in the Settings app doesn't seem to really match what the comments say.
Disclaimer: I didn't actually find where this setting is read, or how it affects anything. I'm just basing my hypothesis off of the comments. I could be totally wrong. Either way, the advice usually given out about developer options is to just not change anything there.
Anyway, what I found:
The related settings preference controller toggles OTA_DISABLE_AUTOMATIC_UPDATE_KEY.
The settings provider entry for this setting has a comment:
Whether to disable the automatic scheduling of system updates.
1 = system updates won't be automatically scheduled (will always
present notification instead).
0 = system updates will be automatically scheduled. (default)