Point taken. Personally for confidential / valuable content that I expressely generate though (not logs or anything done by the system) I feel better when it’s wiped with shred, coupled with periodically wiping all available free space on the host. Needless to say, the HD isn’t SSD.
Let’s take a crypto wallet, for example, electrum. The wallet keys are stored on the HD. If the user specifies a password, they are stored in encrypted form. Now say they were stored unecrypted on a temporary file, which was then deleted and the encrypted file written. I think that would be an unwanted behavior.
Now why would they do something strange like that, I don’t know, but it can happen that sometimes I store self generated private keys on the HD, then I encrypt the file with gpg and shred the original. Sometime I need to import the keys to another wallet. If I edit the original, I certainly don’t want it to be copied anywhere.
All that is probably not relevant for configuration files discussed on the wiki. The closest I can think of is the private key of an onion site, I don’t know, I will feel better not have a file with that info copied anywhere even temporarily. But I would probably use nano to edit it rather than any GUI editor.