Hey, there are two parts to this. Firstly some Unity staff put together a prototype of screenreader support during a hackathon last week:
Secondly, a week before that Unity put out a call for input from developers on what Unity could do 1. to make the editor more accessible to disabled devs and 2. help devs make games that are accessible to disabled developers:
The feedback thread is for developers rather than gamers, so please don't post there yourself unless you're a developer. But if you've ever spoken with a developer who wanted to make their game accessible but couldn't because Unity didn't support it, please please get in touch with them again and ask them to post on that Unity forum thread. Showing them the link to the prototype tweet might help show them that asking Unity to implement screenreader support is now something realistic to shoot for.
Feedback from devs is important. The screenreader support is only a quick prototype with no guarantee of making it to release, so any demonstrable demand from developers can only help its chances.