They do stuff like that. They also killed "Robot" personality last year which was my favorite. The replaced it with "Efficient" or something, but it isn't the same. Robot was terminator-esq, appropriate for the new age we are entering IMO.
They recently made "efficient" even more verbose, my custom instructions can't suppress it properly anymore.
These "little" changes are incredibly annoying.
Codex has also been fine, but I'm guessing they know better than to tweak it like that, given their target users.
But then I just switch to another OpenAi and strangely enough, chat forces me into “thinking mode” when that happens and won’t let me do instant