What is the correct holding altitude for the missed approach at Unalaska (PADU)?
That note actually refers to the holding pattern in general, not to the missed approach procedure. Your reading of the missed is correct.


  Descend to 6000 in holding pattern.


Refers to descent from the MSA or any other enroute altitude. Before transitioning from enroute to the outbound initial segment (departing the IAF) the pilot must descend in the hold to 6000. Once leaving DUT outbound, descend as specified to 4700.