So I went and looked through all of One Drive and I don't see any files differing from the same ones on my actual computer. When I look through my files for the game on One Drive, they're the exact same as the picture I attached; none of them being modified since June. The only thing that I saw had been modified after June was a lock file that says it was modified in August. And I've confirmed that those save files, both on my computer and the cloud, are just saves of those throwaway games I hadn't worked on.
Even so, I turned off one drive before I started the game that had all my builds and households, so I would have assumed it wouldn't download onto the cloud, just on my computer? I haven't deleted anything related to the Sims since then, so I'm not sure where those saves could have gone at all.
And no, it doesn't seem like there's anyway to check for an older version.