I was adding context that "using the whole song" like the person I responded to is irrelevant. The entire point of the lawsuit is the vocals, not the use of the song.
Edit: Also disproving the claim he did it without permission

That's because the agreement was for something like a few notes of the original song, not interpolation. Interpolating is literally rerecording the same song essentially, instead of sampling like Verve had alleged in their agreement.

Besides this lawsuit isn't even about the song itself, it's about them having someone essentially impersonating Astley. Not the lyrics themselves.

Those songs do not interpolate. There's a difference between copying a beat or sound and getting clearance to interpolate an existing song

>The rapper and his team allegedly cleared the use of the underlying musical composition of Never Gonna Give You Up, which was written by Stock Aitken Waterman.

>This allowed them to recreate music and lyrics from the original song for their own track, a process known as interpolating.

From the article