Hopefully not. At the very least you would still have to 'OKAY' an update dialogue.I have frozen Motorola update services , and the update notifications have stopped. Rooted and frozen update services via titanium backup. By the way , is there any chance the update could suddenly start on its own?
The 'Preflash validation' error tends to appear in that scenario.And is it impossible to downgrade to Lollipop with locked bootloader? Just have some curiosity...