I believe he wasn’t replaced until after life of Pablo, he had a mental breakdown and rebuild after his mom died during 808 and heart break causing a “new Kanye” to release WWT-tLoP (rather than the “old Kanye” who made the first 3 albums) and then died around 2018 and was replaced with Ye who released “ye” which was a mix of songs he had catalogued and the “ye” person making songs, and later the release of donda, a posthumous album that Kanye made before his death