Transducers are nothing new, and piezo speakers are nothing new. That said, this might improve audio in constrained spaces such as wristwatches, smartphones or laptops, because you can re-use existing larger surfaces.
It will probably not replace traditional speakers due to simple physics: sound pressure depends on displacement volume, which means area * excursion. Piezo crystals are not very flexible and have weakness in sound reproduction. They were used in cheap tweeters for some time, but have fallen out of fashion because at higher volumes they start to "scream" in a very unpleasant way. The higher excursion requirements also means they cannot be used for low frequencies. Acoustic short-circuit also means that you cannot just have a thin paper-like loudspeaker, as the waves from the front and the back cancel each other out (this does not apply to wallpapers).
It will probably not replace traditional speakers due to simple physics: sound pressure depends on displacement volume, which means area * excursion. Piezo crystals are not very flexible and have weakness in sound reproduction. They were used in cheap tweeters for some time, but have fallen out of fashion because at higher volumes they start to "scream" in a very unpleasant way. The higher excursion requirements also means they cannot be used for low frequencies. Acoustic short-circuit also means that you cannot just have a thin paper-like loudspeaker, as the waves from the front and the back cancel each other out (this does not apply to wallpapers).