Comment by Fiveplus

The whole text regarding this reads:

"We’re exploring preloading File Explorer in the background to help improve File Explorer launch performance. This shouldn’t be visible to you, outside of File Explorer hopefully launching faster when you need to use it. If you have the change, if needed there is an option you can uncheck to disable this called “Enable window preloading for faster launch times” in File Explorer’s Folder Options, under View. Looking forward to your feedback! If you do encounter any issues, please file them in the Feedback Hub under Files Folders and Online Storage > File Explorer Performance, or Files Folders and Online Storage > File Explorer."