There's over 1100 open issues over on the Audacity git, though… so, you know…
Still, this should be a fairly easy thing to implement, I would guess. Though I'm not a coder, unfortunately.
But last time I complained about this, @Torstein very kindly just whipped up a website that converts the Audacity .txt export of the labels track to a chapters json file pretty fast, though. So… http://altin.no/track2title/
Here's hoping someone wants to do this, even if it's not the most critical thing.