What will happen to a host if it is not assigned a Sensor Update policy?

The option that describes what will happen to a host if it is not assigned a Sensor Update policy is that the host will use the Default Sensor Update policy. A Sensor Update policy is a policy that controls how and when the Falcon sensor is updated on a host. You can create and assign custom Sensor Update policies to different hosts or groups in your environment. However, if a host is not assigned to a specific Sensor Update policy, it will inherit the settings from the Default Sensor Update policy. The Default Sensor Update policy is a “catch-all” policy that is enabled by default and has the “Uninstall and Maintenance Protection” feature turned on. You can modify the settings of the Default Sensor Update policy, but you cannot delete or disable it1.

References: 1: Falcon Administrator Learning Path | Infographic | CrowdStrike