As far as I understand it a appearance preset is set for the version you made it from. If another version of the person comes along it depends on how much has changed in the new one and if you kept the older version. For example, if you have both versions and the textures were changed but kept the same name, then your app preset will fetch the ones for the older version. If you don't have the older VAR it will try to get the textures for another version of the VAR, as long as the paths/filenames are still working.
If in the new version the paths are different or there's different information like new textures or different morphs that weren't part of the older VAR, then you'd have to make a new appearance preset from the newer VAR. You can load them side by side and see which you prefer or merge them with built-in tools or some plugins. Personally I would check them side-by-side if there's substantial changes on the preset, I tend to tweak a lot.
