I'm the Accessibility Product Manager at Slack. We have indeed been taking steps to improve Slack's accessibility, my worst nightmare as a PM is for people to not be able to perform in the workplace because of Slack.
For the last 6+ months or so we've been focusing almost exclusively on the screen reader experience. Tomorrow we're releasing a new round of improvements and we'll update this article with the details -
$1. Oh, and we also got some JAWS licenses.
Please continue to send us feedback & especially criticism, all accessibility messages make it to the accessibility team (yes our Customer Experience is amazing) and I read & further triage the majority of them.
Also, please feel free to AMA