No.
While the new signup flow introduced in 2024 now guides administrators towards creating a managed Google Workspace environment, there is no cost to this, and domain validation is optional.
Furthermore, should an organisation choose to opt out of Google Workspace, they can continue creating a bind with a standard Gmail account, and the EMM will create unique and generic managed Google Play service accounts on each Android device that allow sign in to the Google Play Store for application management as it has always been.
The greatest benefit to using a free Google Workspace environment comes from identity, allowing managed devices to authenticate as users in the company domain in order to benefit from user assignment and user-based policies. Google have additionally expanded the signup process to work with Microsoft 365 accounts to tie in automatic external identity management within Google Workspace, removing an additional SSO integration requirement.