An interesting tangent is that this could entail the extinction of several human-designed strains of animal which are not well equipped to live in the wild.
So mote it be I guess.
Base genetics are still around for the chicken, pig, and sheep, but the Aurochs's extinction means we irrevocably altered the cow. I'm sure a few varieties of cow would adapt to the wild though.
Buffalo may need to keep their vestigial wings too.
More broadly, the answer is that it doesn't really matter that much. Species go extinct all the time, and with humans around the rate has been astronomically higher. Replacing animal products with plant based or cell based products might even have a net benefit in extinctions, since land that would otherwise go towards feeding and raising livestock could instead be let back to nature.
Simple:
If the animals were freed they would destroy the ecosystems they were freed in (all ecosystems).
They could all be killed so they don't cause any impact.
The animals would be suffering from pain, illnesses and slow deaths just as nature intended.
Animals would not turn vegans.
The world would probably suffer a supply issue.
Everyone would be weak, unhealthy and have a lower lifetime cause of their horrible diet.
Everyone would be hypocrite as they kill plants and don't feel remorse just because they're killing something that can't walk and doesn't have eyes and mouth.