I’m going to be much more positive for you with much respect to the previous poster. As you say you’re all paid up and there’s no going back, so don’t worry and look in the bright side. We have done Coastal cruises almost every year for the last 20 years, spring and fall and the smoothest one we did was actually late October. The Sea was like glass. You just never know. Regarding Alaska, October is not ideal, with the shorter days, but a sad effect of climate change seems to be the nicer weather for longer.
As far as testing, without a crystal ball, I don’t see it being dropped as it was part of the conditions for ships to sail out of Canada this season.
Im sure you’ll wonderful trip!