If it was supposed to get riders wet, why did the designers test out the drops while wearing business suits? Here's proof from Rollercoasters, Flumes, and Flying Saucers (a great read about Arrow Dynamics and focusing on DL's early development, if you haven't checked it out):
At the time that Pirates opened, Disneyland was still a place where guests wore their Sunday best. Sure, they could get a couple drops on them, but nobody was looking to get soaked. It wasn't until the amusement park building boom in the 1970's that rides designed to intentionally get riders wet (like log flumes) became commonplace.