We are continuing to update classic SharePoint experiences to be used in our newer user interface as well. The following list templates now have updated user interface support:
Issue Tracking List
Custom List in Datasheet View
New and existing lists created using one of these templates will now appear in the “modern” UI by default.
Modern issue tracking
Additionally, the modern UI now supports multi-line text fields with the "Append Changes to Existing Text" setting enabled. Lists that contain this field type will no longer fall back to classic mode to accommodate these fields.
We'll be gradually rolling this out to Targeted Release customers in late June, and the roll out will be completed worldwide by mid-July 2018.
We are continuing to streamline document creation and sharing throughout Office 365. Soon, we will align creating new files in document libraries with file upload transactions. When a new file is created (using Office Online) in a library by clicking the New button and entering the required metadata, the file will no longer be checked out automatically to the user who created it. This allows other people to see the file even if required metadata has not been specified yet.