Suggested at T298881. The idea is that when the bot goes to post a message, it checks for a local template (which can be in the userspace), say User:Community_Tech_bot/CommonsNotificationMessage, and substitutes it if it exists, instead of using a raw message. This allows the local community to tweak the wording as desired. In the case of Chinese Wikipedia, specifically, it would allow them to use the MediaWiki-Language-converter so the message can be shown in both zh-hans and zh-hant.