From what I read its not about the lyrics alone. He is claiming the label conspired against him (via bots, payola and unfair practices) to damage his brand value for the contract negotiations. The song is just how they went about doing that because they were aware the impact those lyrics could have on his brand. Basically saying the label deliberately amplified the damage the song did.
You are forgetting that there's two separate lawsuits. The second one is strictly about UMG allowing Kendrick to release a diss song to Drake with 'lies' on it, while neglecting that they let him do the exact same thing. It's like walking up to a man, punching him, he knocks you out and you call the police
I mean conflict of interest would always be a problem when two artists on the same label are beefing. Can Kendrick say the same shyt? That UMG devalued Kendricks brand by allowing damaging lyrics by Drake to him and pushing it.
Also, why would UMG want to damage one of their most prized assets? They make money when he does, if he generates less they generate less.
Even if Kendrick won the beef, Drake is still a bigger cash cow and bigger artist. He might have less stans, but more casuals. That is, of course, assuming that Drake actually is profitable. Which I, and his stans, believe he is.