It will be interesting to see how The Mandarin is handled in Shang-Chi and the Legend of the Ten Rings. The bait and switch that Marvel pulled with an actor portraying the villain in Iron Man 2 was one of the few times that fans really had a problem with a choice made for the MCU. I'm glad there's a second chance to get him done right.
The Flash and Iron Man have shared adventures on the blog before - They were last seen together in STF #2546, and had a two-part tale that began in STF #1164 and concluded with their future counterparts in STF #1165...
