According to CanonRumors, Canon EF 70-200mm f/4L IS II USM lens currently is in development. The old version lens has released for over ten years. According to the source, the new EF 70-200mm f/4L IS II USM lens will be announced sometime in 2018.
The new lens would be the most advanced zoom lens in the Canon lineup. It is slated to come before an update to its f/2.8 bigger brother.