Which journals or conferences have publication accessibility requirements?
Working from the guidelines you linked: http://www.si.edu/Content/Accessibility/Publication-Guidelines.pdf, I think APA style (and probably many others) meet many of the requirements. Most of the accessibility recommendations relate to the final printing (e.g., matte paper) and not to the electronically submit manuscript. APA style recommends 12 pt Times to be used as the font with double spaced lines, 1 inch margins, and a ragged right margin, which seems to tick all the typesetting rules apart from the use of a non-recommended typeface (but as a translational typeface with high quality printing it might still be accessible).