Via an Intune notification yesterday evening, Microsoft informed all Intune tenants that in September, Intune will deploy the Azure Authenticator app as a required app to all users by default from Google Play. Do note that later this year when the Android Intune Company Portal application is updated, Office apps will no longer be supported without Azure Authenticator and Conditional Access users will be quarantined.
Today, you can find the application here
You can in fact opt out by navigating to Mobile Device Management > Android node in the Intune console (once the update is deployed to the tenants)
Start preparing now!