New Installs of UNVERIFIED third-party Apps will be Blocked in domains starting July 8, 2019
Apps using sensitive or restricted scopes must be verified through the Verification Process in order to avoid certain restrictions. This is a new restriction starting July 8, 2019.
Google cares about security and privacy, and this is why actions are being taken to protect general access to user data.
If your app is verified, then this will not affect you. This security policy is specific to third-party apps being installed in domains (Eg. GSuite). What is NOT a third party app? An app inside of GSuite isn't a third-party app.
What is the difference between this new policy, and the existing requirements for apps using sensitive and restricted scopes? Technically, the existing policy governs apps accessing user data for non-enterprise accounts. This new policy affects domains. (enterprise accounts, Eg. GSuite)
Anyone who has already removed sensitive or restricted scopes from their publicly published app and/or been approved through the OAuth API Verification process, doesn't need to do anything.
Even though this new policy is specific to enterprise accounts, most developers who wanted their app published to the GSuite Marketplace, have probably already taken action. So, in that sense, the new policy really has no new implications for those developers.
I am not an official source of information on this topic. This post is my personal understanding of the information that is publicly available.