When you add a link to a project or task in a task / comment, and (some) people that follow that task, don’t have access… Especially when transparency is default (this is even part of Asana’s culture as they officially define it :)), this is extremely annoying. We have dozens of these conversations per week: http://img.springe.st/20190102-xmeio.png
The underlying problem is that people see different things of course. In my example, Debbie just sees her project or task, and I see Private Task. But she has no way of knowing that…!
IMO the fix is not too complex and does not have to lower privacy: simply show a tooltip / icon when you do this, so you have an extra reminder in case you do want people to be able to read what you’re referring to.
Or, of course, to improve privacy by not accidentally adding people as collaborators who should not even read what you write…
Let me know if this is unclear please!