A Microsoft file hosting and synchronization service.
Just to add - on top of the dreaded URL shortcuts, this update broke some scripts I am using to deal with Live Photos that call OneDrive API. So, digging deeper, it seems that the root cause that no-one from Microsoft is willing to admit is that they're migrating users from the old OneDrive backend (API endpoint https://api.onedrive.com/v1.0/ ) to a new SharePoint backend (like OneDrive for Business is using, API https://my.microsoftpersonalcontent.com/_api/v2.1/ ). You can see these links i.e. in browser developer tab when using OneDrive, but for now it does seem to correlate to the missing/present "Search" in settings indeed.
I just wish they'd migrate whole family subscription at once, this is beyond user unfriendly.