> When you delete a file from Windows 11 on a typical hard drive, the file isn't deleted immediately. Instead, the operating system tells the hard drive it can overwrite the physical area of the disk where that data was stored the next time it needs to perform a write. This is why it's possible to undelete files (and why deleting files in Windows doesn't typically clear much physical disk space until you empty the recycling bin).
I think the author is confusing move to trash (which is just updating directories) and marking sectors as available which means they may/will be overwritten when needed.