This is the kind of adjustment to internal parts and service advice all companies that care about their customers give out to their service departments as a continual ongoing practice.
Releasing it like this, with no context, or the numbers or percentage of affected units, as Canon know very well, will just cause hysteria amongst a vocal few, many of whom won't actually own the lens, panic amongst many that do but don't have the "issue", inundation of service centers who will not replace anything just because "it made a noise once", and a host of other entirely negative outcomes.
Doing this like this is not a positive thing to do by any measure or rational. You are in a unique position to cause or limit any backlash, releasing confidential documents like this needs to be done with the greatest care, a huge amount of back story and lots of context is needed to justify disclosure of this kind of information.
You have a rational point on this. However, as I stated in another thread, the lack of integrity Canon has shown its customers (me being one of them) makes me completely unsympathetic. Maybe if they were like Apple and went the extra step to help out and make sure the product becomes satisfactory, even with known issues that might not affect every unit, then I would support keeping this information confidential. However, Canon almost goes out of its way to insult its customers. I was personally told I was "hearing things"!