Don't assume malice when ignorance is an apt explanation.

In this case, is there a functional difference? Will this pop star suddenly realize that the workers were protesting and join them in solidarity? Or will he go back to his life and continue to ignore the problem?

At a certain point, ignorance and malice qchievw the same effect.

So when you buy a phone made from slave labor, are ignorant of the fact until someone tells you about it, but buy another phone built from slave labor, are you malicious?

Yes, obviously.