Microsoft confirms you really, really don’t need to ‘safely remove’ USB flash drives anymore:
Well, Microsoft is confirming once and for all that — in Windows 10 — it’s no longer a thing you need to worry about. Windows 10 has a feature called “quick removal” that lets you yank a drive anytime (so long as you’re not actively writing files to it), and it’s now the default setting for each new drive you plug in as of Windows 10 version 1809, according to Microsoft’s own support guidance. Basically, “quick removal” keeps Windows from continuously trying to write to a flash drive, which could help in the event you disconnect it.
https://support.microsoft.com/en-us/help/4495263/windows-10-1809-change-in-default-removal-policy-for-external-media