To me, "bare metal" has always meant, "without an Operating System".
With ARM Cortex MCUs, one does not muck with registers like on an AVR.
Use vendor-provided Hardware Abstraction Libraries (HAL), for every peripheral I/O device on the chip.
AVR was bare-metal.
ARM, is not.
Which seems to suggest that, to stevech, "bare metal" means, "without the use of a HAL".
Just wondered what others think when they use the term, "bare metal" - are there varying degrees of "bareness" ... ?