Yup, that's been a thread in the comics for a while, at least since New Avengers and Civil War. And since RDJ is the anchor of the MCU, it's no surprise that they'd embrace that.
Huh, didn't know that. Not a big comic reader, so I asumed it was just something for the movie. I'm curious if this really will be RDJ's last appereance in a MCU movie. I know he signed on for a few more movies after his contract ended, but I have no clue about how many.