SharePoint Online is embracing Azure AD more closely by forcing new tenants to use the integration between the two Microsoft 365 components. In addition, site sharing will use the Azure AD invitation mechanism instead of SharePoint’s own code. The changes make a lot of sense and shouldn’t cause much disruption for tenants. It’s a good reminder to check the relevant policies that control external access via Azure B2B Collaboration.
https://office365itpros.com/2023/03/20/azure-ad-b2b-collaboration-spo/
