Simple vocalizations are cool, but that's pretty limited communication, and if they're capable of so much more, it's pretty likely that they're using individual meows in much the same way a human would under the same constraints. Imagine only being able to say "HEY!" and having to use context and body language in every situation.
TheyCanTalk have got n>10k animals so far, mostly cats and dogs, with a handful of pigs, rabbits, goats, and others. I've seen a few horses, cows, and others on social media, too, and they've got a lot more customers than study participants.
Unless they pre-registered that prediction, isn't this just the Texas Sharpshooter fallacy?
> We acknowledge that our sample size limits the generalizability of our findings on cat greeting behaviors.
[0] "We also tested whether demographic factors such as the influenced the amount of greeting behavior expressed by household cats."
This is very funny. Ig Noble prize stuff. https://en.wikipedia.org/wiki/Ig_Nobel_Prize