E911 "GPS" can be disabled unless you dial 911 on every phone I have ever seen.
And I believe the tracking you by cell is because the cell companies work with law enforcement and allow them to watch a numb er as it logs in to new cells as you move (an important part of how the technology works).
You are correct. The location function can be selected so that is activates only when you dial 911, or at least as far as you know
That said, any cell phone can be tracked if it's on and talking to the cell towers. This capability is a least a decade old. The cell companies developed it back in the AMPS days to try to deal with phone cloning and illicit use of the system.