I'm arguing that the incumbents have a built-in, guaranteed communications channel. Any obstacle to speech by the people (whether they're rich or poor) leaves no response to those in power. In effect, then, the rules enforce an oligarchy.
In fact, your argument that the CU decision only benefits the wealthy is precisely the opposite of the reality. In fact, the wealthy don't need to cooperate in corporate bodies to finance public speech: folks like Donald Trump can get up on a pulpit with their own personal wealth. It's only us regular people who have the need to cooperate (i.e., to incorporate into a body to handle the demands of our effort).
Thus, CU is a benefit to the regular guy, without having much effect on the opportunities available to the rich who can go it alone.