Headline effects only take place after they're placed, so they only apply on future actions.
Yes, I understand this. My question is indeed about future factory placements: suppose you place 2 factories in a future turn, do you get 1 or 2MM from the Gilded Age headline?
Wade is correct, the intent was for players to receive 2 VP and 1 MM per Factory. So, if a player builds or places 2 Factories then Gilded Age would give them 4 VP and 2 MM.
For reference, the card Headline states, "A player scores 2 VP for each Factory they build or place, and then may use 1 MM immediately." The way the last portion is read does leave it open for interpretation. I would change it to say, "A player scores 2 VP and may use 1 MM immediately for each Factory they build or place."