There are two accessibility features of the Apple Watch that stand out to me: Extra Large Watch Face and Zoom. Regarding the Large Watch Face, it does what it says: shows the time in a ginormous font. It's very well done, although for my needs, I'm confident that I can get by just as well with Large Dynamic Type. Overall, however, Large Watch Face will be great for those who need the clock to be extra big in order to read it. Likewise, the Zoom feature was helpful for me in identifying icons on the Home screen, as they're a tad small at normal size. I found that Zoom works best for me using the digital crown, as the two-finger pan was more difficult to do using my partially-paralyzed right hand (caused by my cerebral palsy).
As he suspected, Force Touch could play an important role for people with disabilities.