Hayotze Min Hatamei Tammei, so I can’t really imagine anyone serious being Mattir something grown from Treifa meat.
As to Popa’s Taana, I think that even more than the nuances is the texture. By just growing cells it won’t be a steak. If they will want to duplicate a real piece of meat they’ll have to intersperse different cells. That will definitely be artificial. It will probably do well as a cold cut.