We’ve just merged a patch into the 10.1 code branch that alters the way advanced reboot options are presented to you as an end user. As of the next nightly, by default you will no longer see the sub-actions for ‘Recovery’ and ‘Bootloader’ when selecting ‘Reboot’ from the power menu.
To re-enable those sub-actions in your power menu, you will now find an ‘Advanced Reboot’ setting in ‘Developer Settings’. As a note, even when enabled, you will not see the sub-actions in the reboot menu until the device is unlocked; the sub-actions will never be available via the lockscreen.
This change should mitigate accidents when children or others use the device, and put up an obstacle for pranksters or more unscrupulous persons from wiping your data to access the device; they must know the hardware key combination to get to recovery. At the same time, the option to re-enable this sub-menu should appease power-users and the like for flashing and backups. With the widespread use of CMUpdater and other GUIs for flashing, we recommend that most leave this option off for that added layer of protection.