Donny, if you checked the site, you will quickly see that all the Genos and SX styles have been converted to used with the older keyboards, and they sound fantastic.
As for Yamaha leaving a player stranded, I have never experienced this in all the years I have played Yamaha arranger keyboards. When I am left scratching my head for a song specific style, I just dig into the style library and usually find it in a short time. Or, I go onto the forum and under the Styles section, request a style for that song, which I have only done once in more than 20 years. Most of the time, I post styles for others to use, or recommend one on the keyboard that is suitable.
Gary