Looks like they’ve taken down the fan versions of the song for copyright reasons. Fans had been making their own recordings of Now And Then by adding backing tracks to the existing Lennon vocal track. These had been circulating for years including on Youtube and some were quite good. Interestingly the fan recordings included a verse which was on Lennon’s cassette track but which the Beatles edited out of their version. The verse had lines like “If I ever used you, ever abused you...” which didn’t fit the vibe of the song. IMO they made a good decision to leave it out of the finished version.
Ringo Starr on New Beatles Song: It’s ‘a Nice Way to Finally Close That Door’
https://www.aarp.org/entertainment/celebrities/info-2023/ringo-starr-interview.html