cultivated beef does not cause any harm to animals - meaning the cow can live happily ever after.
That's not true. If cows will not be used for meat/milk. they will not be bred in such quantities as now, which means they will not live&die, they just will not be born.
My biggest concert for cultivated meat is that it has a potential to disrupt small-scale livestock farming (like, family keeping a couple of goats for milking/their offspring for meat), thus closing a possibility for them to live independently.
The centralization of meat production has a danger of making such people dependent on a capital intensive "meat cultivating" facility.