I think people may be talking about two different things here, Orbx Central and OrbxDirect (aka, the Store). As Michael and others noted, Orbx Central detected my MFS Beta installation when OC updated to version 4.1.21. When I deleted MFS in anticipation of installing the release version, MFS no longer shows as an available sim in OC. Clicking on the "Store" tab in OC does indeed only show installed as well as available for purchase add-ons for the selected sim. Going to OrbxDirect I can see the products I purchased for XP11 (no longer installed). As for FSX, it seems to be merged with P3D. I doubt I ever had FSX products that I didn't also have the P3D version for, so for that, I can't tell, but it's irrelevant to me, since I long ago removed FSX.