Qualcomm may be set to announce the release of the upcoming Snapdragon 845 in December, eleven months after the launch of its predecessor. There's also a chance the new SoC won't make its way into public hands till Q2 2018 when the S9 is released.
https://www.notebookcheck.net/Qualcomm-slated-to-release-new-Snapdragon-845-in-December-Samsung-Galaxy-S9-with-first-claim.261038.0.html