MS switching M365 Apps semi-annual update channel to monthly unless opt-out

TL;DR, You'll need to opt-opt before May 20 if you wish to keep any current installs on the semi-annual update channel.

> If you don’t want your Office installations to be switched to Monthly Enterprise Channel, in the [Microsoft 365 Apps admin center](https://config.office.com/officeSettings), choose 'View details' on the notification (top right bell icon), and then choose Keep my devices on current configuration before May 20th.

https://admin.microsoft.com/AdminPortal/home#/MessageCenter/:/messages/MC362760?MCLinkSource=MajorUpdate