ArcGIS Online is updating April 13th. One new big thing is a new Map Viewer! Before you get too excited (or worried), the old one isn't going away and will remain the default in your org, renamed to Map Viewer Classic.
- GeoInquiries will continue to open maps in Map Viewer Classic through the end of the school year. You will get a notification when you first open a map about the availability of a new Map Viewer. Click "Not right now" to continue with Map Viewer Classic.
- Entries to the Schools Mapping competition are expected to be using Map Viewer Classic, and no "extra credit" will be given to students for using the new Map Viewer.
While the new Map Viewer is bringing some great enhancements, don't let it disrupt your teaching as the school year wraps up. You can explore it and maybe test out a few of your maps in it, but there is no reason to change and use it with your classes this school year.