To be honest, some came on board on 2012 when the first Avengers came out. So it in fact varied whenever some came on board to the MCU. Some it was 5 or even 6 years before Endgame give or take. I was in theatres with kids that did play catch-up to the MCU, and went as far as Skipping school to see Avengers Endgame. My Showtime in Raleigh IMAX Marbles theatre across from the kid’s museum was at 1:00am on April 26th. I was definitely among the few million that was at Theatres before theMCU and since Iron Man one when my late night show time actually had few people in theatres and people within our community would ask “ who’s Iron Man?”