Speaking to Empire Magzine Cumberbatch said this while he was asked for the future of Dr. Strange in MCU :

Logistical challenge of aligning his schedule with those of Robert Downey Jr, Chris Hemsworth, Elizabeth Olsen and Paul Bettany

Now do I need to say more about it? Yes, he is possibly talking about Avengers : Infinity War.

“To get us all together will be quite something,” Cumberbatch continued. “That’s why this character is being introduced, to open up the next chapter. So watch this space to see how that unfolds.”