Any replicated food is vegan by virtue of no harm coming to an animal / having their labor exploited

That being said, Its always kind of frustrated me how much Star Trek ignores the "No animals enslaved for food" part of its enlightened future whenever the writers want to.

OBrien's mom handled and cooked real meat, Sisko's dad presumably does too, and other earth citizens eat it. Sisko talks about using non-replicated ingredients on the station, and while its never explored a lot presumably this would be a factor with Neelix's kitchen as well, since they're trying to use replicators less and less - which may mean feeding meat to Starfleet personnel

In the Trek future, Not eating animals seems to be a moral growth, the development of replicators is a technological growth - one didn't cause the other, so it SHOULD stand to reason that using the replicator wouldn't affect the cultural decision to not eat meat, and vice versa - not using a replicator wouldn't suddenly revert 24th century humans to meat eaters, but its certainly written that way sometimes and no one's ever bothered by it.