No it doesn't. It says "Hey boos I'm telling you this shit is not cool, and there's nothing you can do to me personally because you don't know who I am."
Let me put it differently. Suppose YOU are the boss. You company has 1000 employees and you receive a letter with 500 anonymous signatures saying "we fucking hate what you're doing" (so, 50% of your employees, 100% anonymous). Do you get a little bit worried? Or do you get not worried at all because everybody signed anonymous? Actual question, let me know how you think.