Yes, I did something similar: prior to disabling Siri, I set Siri's language to French and kept the system language set to English (UK), but the Siri AI.app ("Siri" process in Activity Monitor) just keeps running despite Siri being indicated as disabled in Settings.
replyIf you are on macOS 27, could you please open Activity Monitor, search (filter) for "siri" and see if a process called "Siri" is still running?
You are right. The UI shows Siri disabled and offers to turn it on, but the process is still running. That process seems to change its name based on whether the UI thinks Siri is enabled; it can be called either just "Siri" or "Siri AI" but it’s the same executable.
replyFWIW it's entirely possible (and not uncommon) for a single executable to behave differently depending on the name it was launched under.
replyI have no idea in this case, but it's possible that "Siri" and "Siri AI" are genuinely different in behaviours and interfaces and dependencies, even if they are the same binary.