After a quick search, there is no scientific evidence of any aphrodisiac effect of oysters.
As I like facts (and oysters), I will avoid implementing such thing... ;-)

I know it isn't real, it's just been a myth since the Roman Empire. Worth an ask! Thanks!

Lol I really like this idea ^.^ I think oysters bio-engineered to produce artificial aphrodisiacs growing wild on a Rimworld would be welcomed in the games lore-- don't overwork yourself tho! The forbidden mod has mushrooms which do the same but they cannot be farmed that I'm aware of, its a niche that hasn't been filled but I can appreciate your disinterest