I would suggest self-publishing. There's a gentleman in my office in Calgary who lost his sight as a result of having water on the brain. I think it's hydrocephaly. He went from having normal vision to being legally blind literally overnight. He self-published a book that you can buy on iTunes for $10. He went through the same channels as you folks would go through when you decide to publish your memoirs.
Those platforms are available. Some are better than others. That's the same as anything else. There are good cars out there and there are bad cars. There are good self-publishing platforms that are usable by someone relying on assistive technologies and there are those that aren't. The natural market progression would be that when and if folks with disabilities choose to publish, they will find by trial and error those tools and those systems that work well for them. Those will be the ones they patronize, and hopefully, those will be the ones that last.