Wacom posted this today on their support page and on their Facebook page:
.Apple has announced 10.13 High Sierra will be released September 25th. Wacom is currently working on a new driver update to support the new operating system. The new Wacom driver will be ready by late October at the latest. Due to nature of the changes in High Sierra, the existing Wacom driver for 10.12 will not work. To continue to use your tablet uninterrupted, Wacom suggests not to upgrade to 10.13 until the new driver is released. Once released the driver update will appear in the Wacom Desktop Center and will be posted on the Wacom driver page .
So , Mac users, don't update to Mac OS 10.13 High Sierra before Wacom releases the new driver in late October (and I would wait a bit to read user feedback reports on whether the new driver actually works !)
Happily still using El Capitan here .