The next update for ArcGIS Online is scheduled for the evening on Wednesday, June 24th. Hopefully it will not break anything or be down for a long time.
Restriction on publishing multiple services from a single data source
Prior to this update, organizations could publish multiple supported services from a single eligible source data item, creating a one-to-many relationship between source items and published services. To align with existing publishing restrictions, ArcGIS Online will now enforce a one-to-one relationship between supported source data items and published services. With this change, only one service can be published from each eligible source data item type. Hosted Feature Services are not impacted by this change and will continue to support the creation of multiple child items, such as Tile Layers and OGC layers. Organizations that currently publish multiple services from the same source item will need to create copies of the source data item to continue creating additional services.
Update to the introduction experience in the ArcGIS Instant Apps Nearby template
Instead of choosing between a single introduction window or information panel experience in Nearby, app authors will now have the option to use both the information panel and introduction window together, enabling more effective in-app guidance for users. As part of this change, any existing app currently configured to use the introduction window as a splash screen will require reconfiguration of any custom text after the update.
Retirement of Standard Industrial Classification (SIC) based business summary variables
Prior to this update, users could continue using Standard Industrial Classification (SIC)-based Business Summary variables within Esri Demographics workflows and analysis. With the June ArcGIS Online update, Esri will discontinue support for the Standard Industrial Classification (SIC) based Business Summary variables as they have not been updated by the U.S. government since 1987. Users should plan to migrate from SIC to NAICS code-based variables to avoid their work being impacted.