We reported previously that the next “L” lens from Canon would be a prime. We don’t know the focal length, but the 35mm f/1.4 is the likeliest candidate for replacement.
Canon hasn’t released an f/2.8 zoom since the EF 24-70 f/2.8L II, but that could be changing some time in the next year. We’re told An f/2.8 replacement for the EF 16-35mm f/2.8L II is likely and that the focal length could change slightly, something like an EF 15-35 f/2.8L was suggested.
If you look at the lineage of the current lens, it has changed focal lengths a couple of times. The first in the line was the EF 20-35 f/2.8L and then the EF 17-35 f/2.8L and most recently two version of the EF 16-35mm f/2.8L
Event photographers still crave the fastest lens possible for the job, and the EF 16-35mm f/2.8L II could use a performance refresh.
I don’t expect such a lens to arrive any time soon, as the manufacturing demands of the EF 100-400mm f/4.5-5.6L IS II and EF 11-24 f/4L probably won’t be quelled for quite some time yet.