I understand - I have lost many things over the years, as well, including stuff where I had accumulated large libraries.
I DO try to retain stuff, when I know it is going to go away - this is why I have kept 1 computer that runs 32-bit XP Pro, and 8.5.3, as there are things that run there and only there.
I don't know how the arrangements are between Cakewalk and the companies that they get software to bundle into Sonar are made. It looks like there is no guarantee of any kind of 'forever' arrangement, such as if the developer quits developing a particular component. That is likely some kind of dark and murky legal stuff.
The 32-bit to 64-bit change was a HUGE deal, and there was a lot of fallout in that shift. I had a large number of freeware 32-bit synths and effects that I just cannot use any longer - hundreds of them, unless I work on a project that needs them in a 32-bit Sonar. This could mean going back to an old XP Pro computer.
I made a deliberate choice to just walk away completely from using 32-bit 3rd-party stuff. It hurt, sometimes a lot, but in the long run, I will benefit from it. By running all 64-bit 3rd-party components, my X3e is the most stable release I have ever had - neck and neck with my 32-bit 8.5.3 version.
Bob Bone