The article claims they did, but the author uses a paraphrase instead of a direct quote. From the article:

"No problem. Qt works on Linux, Mac and Windows, and if you find any problems, just report them to us and we are going to fix them."

However without a direct quote, it's hard to tell if that's an accurate representation or not.

They don't mention any screen readers; their documentation only calls out backend accessibility specs without any mention of popular specs (UIA) they don't support.