Currently large folders (>10k items) cannot be deleted from OneDrive and SharePoint Document Libraries on web. With this new feature, users will be allowed to delete them. The process of deleting a large folder will be the same as deleting any small folder on the web today.
When this will happen
Microsoft will begin rolling out in mid-March and expect the rollout to be completed by early April. Note: Some users may see this feature before other users within your organisation.
How this will affect your organization
Users will now be able to delete large folders (>10k items) OneDrive and SharePoint Document Libraries on web.
If a user tries to delete a shared folder that another user has already started deleting, they will see an error message, “This item is already being deleted.”
Deleted folders will still be available in the site Recycle Bin.
What you need to do to prepare
No action is required.
Aaron Rendell 