Motorola hasn't delivered a proper flagship in the last two years. That may be set to change in the near future, however, as a new report claims the company has its sights on a true flagship device that will sit above the sub-premium Moto Z line.
https://www.notebookcheck.net/Motorola-is-working-on-a-proper-flagship-phone-Finally-a-true-Moto-Z2-Force-successor.440365.0.html