Some organizations today use the 508 standards when designing websites, but those technically only apply to government-owned websites. A decision by DoJ to apply ADA to websites more broadly, would have impact on higher education as The Chronicle article states, and also on public school websites as well.
This has been an issue I've been pushing for years. Public schools take federal funds, but many don't consider access issues when they put their websites together. I have taken to task, the folks at District Administration for a while on this because when they used to review school district websites they wouldn't mention accessibility. I think they got tired of hearing from me, because they've been better the past year. They also did mention the issue in an article they did a while back.
The problem however, is most folks don't have a good understanding of equity and access issues. I did a workshop this spring on equity and access for the Innovations in Online Learning conference sponsored by the UT Telecampus. After my session, one of the participants came up to me and said she'd not ever thought about color schemes for her online courses even though she has a son who is color blind. (I had started the session with some of those simple color blind tests.)
It's clear this is an issue that needs more than just a statement that websites should be accessible. There will need to be more training done to increase awareness of just what that means.