Interesting question. I think this has been discussed before.

When you bought the Tyros you bought the styles, didn't you. So they give you the exclusive right to use these styles and do whatever you want with them.

On the other hand, some styles are a replica of original songs. Like the Pink Panther style. I'd ask if Yamaha had paid to the copyright owners of the Pink Panther theme to use their song as a style. Could you use the same style for your copyrighted song.

Kind regards,
George