There is a song called “Rich Girl” that MJ worked on with Brad Buxer around the time he started seeing Lisa Marie. Apparently it’s decently far along in terms of completion, so says Buxer. No idea of what the status of that snippet is though.
The fandom wiki is frustrating. Tons of great info, tons of misinformation. 99% of the songs labeled “lost” aren’t lost, they’re just unreleased. I’m sure there are some tapes that no longer exist or are missing, but songs recorded by Michael Jackson in the 1990s absolutely aren’t lost haha.