The "metagame" in Magic the Gathering or Starcraft revolves around the game before the game is played. For example, if I see that my opponent in Starcraft is a Terrain player (and I'm a Zerg player), I can study their games and see that they prefer to open 8-rax 3 marines very early harassments.
I then decide to practice 9-pool / 6-ling and make sure I'm good at that before the game even starts, so that I'm well practiced against what they like to do. That's the "metagame", decisions you make before the game even starts.
Or in MTG, its knowing how good Rakdos decks are (or whatever is popular today) and finding counter-cards. You play the game before you even start the game, because you have to prepare your deck.
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So there's no real "metagame" in Factorio. There is a "meta" however. (IE: what most players tend to do).