When you transfer billing ownership of your subscription to an account in another Azure AD tenant, you can move the subscription to the new account's tenant. If you do so, all users, groups, or service principals who had role based access (RBAC) to manage subscriptions and its resources lose their access. Only the user in the new account who accepts your transfer request will have access to manage the resources.
Reference:
https://docs.microsoft.com/en-us/azure/billing/billing-subscription-transfer
https://docs.microsoft.com/en-us/azure/billing/billing-subscription-transfer#transferring-subscription-to-anaccount-in-another-azure-ad-tenant