@geko sorry I missed this!
I’ll make sure this either gets added back to the capabilities taxonomy, or that we clearly communicate the current state of its support and plans. It might be early next week before I have an answer.
Again, sorry for not seeing this sooner.
Keep on using speechSynthesis. We’ll get it added back to the docs shortly (might take a week or two).
Sorry for the confusion, and thanks for your patience!
Thank you for the update.