I spent over 6 years near Tokyo. They sold a mixture of quarter horse and the beef you're talking about.
Called it "Wagyu and the horse you rode in on."
Big seller.
"the team can "add substitute players to its major league active list temporarily." Players added who are then sent back to the minors will not be considered to be an optional or outright assignment."
https://www.google.com/amp/s/www.espn.com/mlb/story/_/id/33518093/mlb-drops-regular-covid-testing-keeps-ability-move-games-needed%3fplatform=amp
As a covid replacement, he didn’t have to be placed on the 40 man to appear in MLB, and doesn't need to be waived or burn an option to return to the minors.