More of Elon's lies. And yes, I use the word lie purposefully.
If you mash the right side of the yoke, you will get the horn. But you will also activate the wipers, AP, and voice command. There is no feature that causes only the horn to activate on a mash of the right side of the yoke. You simply get all of the buttons at once and that happens to honk the horn.
Elon says that there is hardware to support airbag horn. I examined the inside of the yoke and the airbag when I installed my Hansshow wheel and did not see any mechanism to do this. Of course I am not an automotive engineer so I certainly could have not known what to look for. However, the software isn't there to do it so once again this will be relegated to the long list of things Elon promises and never delivers.