That could be, but yet shouldn't be. Any change in how you installed your items (disc, download, different product code) does affect install. I bought discs for my previous DD EPs and I couldn't just copy over my old files or install from my backup files. BUT, when I updated to win 10, I could. So, just adding an SP to your game should not have affected your ability to just copy over your old files, BUT maybe it did.
Besides copying in the dccache files, you also have to copy over the old installedworlds files and relevent library files. The library files are needed for the venues. The installedWorld files is for the store worlds. Then, you need the ccmerged file from dcbackup for your premium content items to work correctly.