Correct, based on sensed CG I believe(assuming that it is serviceable.
Actually, the system to which I was referring was not the CG-sensing Weight&Balance system commonly found on freighters, but the air/ground system... which must be serviceable. When hydraulics are not powered on the 744, the air/ground system looks at nose gear strut extension only, rather than the main gear tilt sensors. The W&B system uses torque sensors in the wheel bogeys.
Back in the early days, the 744 air/ground system would shed external power completely if the aircraft sensors said the aircraft was in the air. Additional engine generator not running logic was added to prevent total power loss if the aircraft was say, jacked up by maintenance. These days, power remains on the aircraft and only certain systems go into air mode (and some busses are loadshed).
When the aircraft is tail heavy, the nose gear strut extends and the steering scissor links move closer to the strut (and in range of the air/ground prox sensors).