The following ideas have been marked as implemented:
In the Attachment Viewer Web Application it is now possible to toggle between two layers in the Web Map to view attachments from each layer. This enables straightforward viewing of images from multiple data collection sources in a single, integrated app. More information on what's new in the Attachment Viewer App can be found in this blog post.
You can now update Vector Tile layers without affecting existing styles or modifying item IDs. You have the option to automatically create a historical archived layer with the old data. Here is a blog post on the functionality and the full documentation about the workflow is here.
In Web Scenes, you can now configure layers that are part of a group layer as search layers in the Feature Search options. You can learn about other updates to the scene viewer in this blog.
We also had some ideas for Web AppBuilder which have been implemented at this release:
Visit the What's new in Web AppBuilder documentation page for more information on these and other Web AppBuilder updates.
To learn more about what else is new in the October 2019 ArcGIS Online Update, check out this blog as well as our What's new documentation. Thank you for your engagement with and all the valuable feedback provided to ArcGIS Ideas. Please keep letting us know your ideas, and we hope you enjoy the latest update to ArcGIS Online!