No. The default anti-spam policy protects all current and future recipients in your Microsoft 365 organization after you sign up for the service and add your domain. The only exception is the previously described requirement for standalone EOP standalone customers in hybrid environments
As an admin, you can use the following methods to further refine anti-spam protection:
Add users to the Standard and Strict preset security policies.
Edit the default spam filtering settings in the default anti-spam policy.
Create anti-spam policies that are applied to specified users, groups, or domains in your organization.
For more information, see the following articles:
Recommended anti-spam policy settings
Configure anti-spam policies in EOP
Preset security policies in EOP and Microsoft Defender for Office 365