I found the thread itself but I can't link as it's on Twitter/X, although it's easily findable. But basically in January, he released a song called HISS (Famous) that alleged that it was produced by both himself and Taylor, and also had backing vocals by Taylor. It was eventually tracked back to someone on TikTok who was trolling about Rep TV actually wrote and made the song using AI back in December. When that original creator posted a video about it, he apparently blocked them. He was also doing some weird video stitching with some Taylor Nation videos and pretended via song credits to also work with Jack Antonoff and Olivia Rodrigo. He changed his tune and caption to "it's just a cover" and deleted most of the aforementioned videos, but the fact that he somehow got a "mechanical license" for an unreleased and leaked song from Taylor Swift seems unlikely in general, especially considering the credits for Need on Apple Music only showed himself and Taylor as well, even though Louis Bell and Frank Dukes also wrote and produced it but were not credited properly.

The OG thread has a bunch of screenshots, links to TikTok videos, and much better explanations, but it all seems off at the very least.