From what I understood, this doesn’t apply to Apple’s FileVault.
Mostly metadata leaking from previewing images from other encrypted drives like Veracrypt.
From what I understood, if you attach an encrypted external HDD or open an encrypted virtual disk, then use QuickLook to preview file contents on the encrypted, the previews will be cached on the host machines HDD. So even after you unmount the encrypted drive, there will be some data left on the host machines HDD.
If the main HDD is a trusted machine with full drive encryption, there’s no leak beyond that.
This is relevant to people carrying around encrypted USB sticks and using them on untrusted machines.
The title is click bait-y and there’s an inflammatory, uninformative quote in the beginning of the story.