Might it have been Lyrebird[0]? They're (as far as I can tell) they have the best text-to-speech that you can actually use. It's kinda annoying when Google makes these announcements about their advances in TTS only to reveal that it's not actually something you can make use of, and no, the dataset they used to train their model is not available.

0. https://lyrebird.ai/demo/

Nope, that is definitely not it. It might have been a smaller, AFAIR french startup. The (english) demos were all weather related.

Wow! I can't believe that's an AI.

You can hear the chirps occasionally.