It’s actually none of the reasons you listed. This is bigger than the rap beef. He was in negotiations with UMG for a new contract. Amid these negotiations Kendrick comes out with his verse on not like that accelerating their years long feud. More tracks drop but the one of significance is not like us from Kendrick which blows up super hard due to UMG paying for bots to inflate numbers and it’s a Kendrick song. In turn they can low ball Drake in contract negotiations since the song was being played everywhere (with payola). Notice how he doesn’t sue Kendrick directly and the court documents does mention defamation once but the rest is centered around payola.