Nope. It has been discussed, but without anything coming out of it, in the threads I have seen. I had assumed there
must be a report on it in the bug tracker, but maybe one should check to make sure...
The icon is indeed there on older articles, and the audio does play, so whatever replays it is still in the build, and able to access the article, regardless of whether the speech synthesis is performed real-time on the player's machine (which I have been assuming), or server side and downloaded as an audio file, like is done with digital assistants...
Maybe somebody is simply forgetting to set some flag, or other, that denotes a thumbs-up on sending the article to the text-to-speech engine...
EDIT: ...yep - there is a ticket:
https://issues.frontierstore.net/issue-detail/34938