Welcome back to the forum!You can use Murray's registration program to convert your Tyros5 regs.
https://www.psrtutorial.com/util/best.htmlAnd yes all your Tyros styles will of course work in your new CVP809. You may need to sub or even upgrade some of the voice in the old styles.
But you will find more and even better sounding styles to use in your new keyboard by using Genos, SX900 and some Genos 2 styles instead of the old Tyros styles found on these pages that you can download as AN EXAMPLE:
https://www.psrtutorial.com/sty/yamaha/index.htmlRegards
Drake