I think you’re both right: translating this message is pretty useless, but it could be done for consistency and reading comfort. So I have prepared and marked the template for translation and added it to the aggregate group. You can translate it. 🙂
All translation admins know English, and the message serves a very short-term purpose, therefore I don't see a need to have it translatable.
Right, makes sense, but translating this message shouldn't be a problem, as other messages which "serves a very short-term purpose) in the same group are already translatable.