Worked for me on Pin 12...
Did you also change the line: const byte buttonPin = 2;
If not if you just edited the pinChange line, did you also change the other places that referenced the buttnPin, like the pinMode and the digitalRead?
As for Arduino docs... Not sure why they only showed those two pins...
Edit: The interrupts on other pins is also shown on the Advanced pinout page:
ABX00080-full-pinout.pdf (arduino.cc)
Scroll down to the advanced section
Edit 2: If two pins have the same IRQ number, my assumption is that only one will work at a time. Example pins 1 and 14 and A4 all are IRQ 1...
Probably one reason Arduino did not fully document this on the attachInterrupt page.