Currently, there is no actual accessibility page, so this avoids a 404 in the docs. More fundamentally, though, it makes more sense for accessibility advice to be directly integrated in the docs (which we're doing, for the most part - though we should ensure that we do cover/mention everything where appropriate), so there's no need for a separate accessibility page.
http://getbootstrap.com/getting-started/#accessibility in the old docs always felt a bit of a catch-all of random bits of advice. if we still think some of these nuggets of info are useful, we should integrate them where appropriate rather than segregating them into a separate sub-page that nobody will look at :)