I think the idea was to intentionally disable the speaker in an AirTag you own. The use-case that I think they were describing would be to make it more difficult for a thief to find the AirTag and remove it. Thus, you'd be able to track your stolen bike for longer (and have a better change of finding it).

Of course, this would also make it easier for someone to disable a speaker and track a person without their knowledge, making it more difficult for that person to find a stealthy AirTag.

I'm not surprised that someone didn't think this through. I am surprised at how many people this must have gotten by to make it into production. You'd think that with any AirTag related product, privacy would be more central to the planning.