Whenever I see “go home and bite [his] pillow”, I’ve always assumed the person spoke quickly and/or skipped a word, which the editor thought should be added. It never occurred to me before now that the editor actually replaced a word!
Replacing a word breaks the syntax and brings ambiguity to some use cases involving brackets and quotes that did not have it before.
As I mentioned elsewhere, a similar thing happened with the one space vs. two spaces to end a sentence.
In that last sentence, there is now ambiguity after "vs. " where there was not before. Right now I am on desktop, but if I were to input that sentence on my Android, "two" would be auto-capitalized, even though I am mid sentence.
I see this headed a similar direction.
Cases where the actual verbatim expression may be made more clear with something added in brackets will now overlap with cases where someone wants to replace a word in a quote...
Sigh :(