I am glad for new features like this, it's one of the advantages of having a cloud-hosted infrastructure. If I didn't want new features, I would stay with old software on-prem. Company admins do need to stay on top of these changes and Microsoft needs to clearly communicate when features are coming, how we will be impacted, and how to administer.
Timing is good on this since I am planning a move of 8,000 users from Office 2013 MSI to Office 365 ProPlus.
1. I am moving users in phases. Is there a way to enable Focus just for the users moving to ProPlus. I would like to introduce Focus as a feature in the rollout.
2. If I enable for all users, what will the experience be like for those still on 2013?