“Free” edition is for companies with an Entra ID (formerly Azure Active Directory) plan.
“Pro” edition is for individuals with a Microsoft 365 Personal or Family subscription.
“For Microsoft 365” is for the following:
Small/Medium Business with Microsoft 365 Business Standard/Premium
Enterprises with Microsoft/Office 365 E3/E5 subscriptions
Education with Microsoft/Office 365 A3/A5 subscriptions
Of significance is the ability to use Office 365 subscriptions for purchase eligibility instead of only Microsoft 365. Organizations not yet buying Microsoft 365 E3/E5 now can’t be pushed by sellers to upsize to M365 to obtain Copilot for Microsoft 365. In addition, the following applies:
The 300-seat minimum purchase requirement is gone.
Organizations can use CSP instead of EA to buy, except education at this current time.