Thank you for your interest in participating in the "Drive Metadata" Beta program. When developing new products and features, Google often makes them available first through a Pre-General Availability program to help develop and test the product or feature and get feedback from users before making them available to all users.

The public signup for the Beta is closed. If you wish to sign up, please get in touch with your support or sales representative. Additional signups will be considered on an as needed basis. To be eligible to participate in the Beta program, you must be an administrator for a G Suite Business, Enterprise, Drive Enterprise, Education, Enterprise for Education, or Nonprofit licensed domain.

More information:
Announcement and demo at Next 2019: https://youtu.be/2Oe0bPic6TY?t=710
Help Center: https://support.google.com/a/answer/9292382