The 5D Mark IV is supposed to carry on the tradition of being an exceptional video camera...
As such, for a kit lens it will likely get a new version of either the EF 24-105mm f/3.5-5.6 IS USM or an EF 24-105mm f/4L IS USM Mark II. This will be compatible with the Power Zoom module, that's currently only usable on the EF-S 18-135mm IS USM. Makes sense, for a camera with high hopes for video uses.
USM lenses weren't ideal for video in the past... however apparently the EF-S 18-135mm is using a new type of USM that's quieter and smoother, yet still gives at least 2X as fast focus as the STM version of that lens.
