They've heard that Marvel is planning to debut the Sorcerer Supreme of the Marvel Universe in Netflix's Iron Fist series.
Whether he will be played by Benedict Cumberbatch as he is in the upcoming movie scheduled for next year, or will be shown in a way that doesn't need such a high profile actor to be on set, I don't know. But odds are that the Cumberbatch will at least do the voice.
Iron Fist is expected to be the last of the four solo series; leading up to the Defenders team-up series. It will tell the tale of martial arts master Daniel "Danny" Rand, who masters the mystical force known as Iron Fist.
Netflix's Iron Fist is expected in the first half of 2016. Doctor Strange is scheduled for release on November 4, 2016.