You typically need the piston fully retracted to replace pads, which very rarely happens just by disengaging the park brake.
If you are old enough to have changed a manual handbrake pad, you normally had to screw the piston back in before you could fit the thicker new pad with a "caliper rewind tool" even if the handbrake was off, the electronic parking brake service mode essentially does this for you, or unblocks the piston permitting a rewind tool to work.
> https://www.brakeandfrontend.com/quick-answer-electronic-par...
You typically need the piston fully retracted to replace pads, which very rarely happens just by disengaging the park brake.
If you are old enough to have changed a manual handbrake pad, you normally had to screw the piston back in before you could fit the thicker new pad with a "caliper rewind tool" even if the handbrake was off, the electronic parking brake service mode essentially does this for you, or unblocks the piston permitting a rewind tool to work.
> https://www.thedrive.com/guides-and-gear/how-to-use-a-brake-...
FWIW, I've never found an electronic parking brake I couldn't rewind myself after a few minutes on google.