According to CR, a new Canon EF 70-200mm f/2.8L IS III USM lens is currently in testing by selected photographers. Though currently there is no announcement date for this lens, we can expect this lens in 2019 to 2020.
Currently, below are a list of Canon lenses rumored to be announced next:
- EF 200-600mm f/4.5-5.6 IS USM Lens
- EF 135mm f/2L IS USM Lens
- EF 50mm f/1.4L IS USM Lens
- EF 24-70mm f/2.8L IS USM lens