This is probably and edge case you don't need to worry about. For the most part, you can rely on the user agent for a scraper that cares about these meta tags

This is probably and edge case you don't need to worry about. For the most part, you can rely on the user agent for a scraper that cares about these meta tags to identify itself as a bot (e.g. twitterbot). Since meta tags are machine, not user, facing, I don't think there's much of any benefit in trying to serve the meta tags to a bot that is intentionally trying to emulate a human.