Google has confirmed that it has no plans to release a new Pixelbook this year, let alone next year. In fact, a next-generation Pixelbook, tentatively called the Pixelbook 2, will not arrive before 2023.
https://www.notebookcheck.net/The-Google-Pixelbook-line-will-remain-stale-with-no-Pixelbook-2-until-2023-at-the-earliest.578909.0.html