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
Gary I have used all the converted ones and there are subtle differences on the sound if you compare them.....
they are not identical and lose a bit of nuances thru conversion
due the lacking of the older models samples, effects, and features.
Don't get me wrong they sound ok but not exactly the same.
Especially on my Genos compared to the motl units,
I agree Donny,
Even though not bad they are not close to the origional.
I have the Genos and the S970, so I can compare directly.
Depending on the converted style, there are sounds missing and the drums sound weak.
I had to do a lot of tweaking to make them sound similiar to my Genos.
Back to what Gary said: I do like the variety of styles offered and I use a lot of them.
Each style is used maybe 3 times max.
That way my songs don't sound all similar.
The Genos makes it a breeze to do style assembly.
I have a lot of styles that I created that way to fit my style of music and songs I play.
In addition I created quite a few Multi pads that I use for song specific riffs that I can't play at the same time.
Great thing about multi pads: I can record it very slow to not mess up and play back at regular speed.
Great tools to create the music I want.
As I said: I am a very happy camper.

All the best
Eric