The wording here is bad, but basically CAA supports non browser specific policy and, in some cases, browser specific policy (GSuite offers a "Managed Chrome" policy). Firefox users can leverage much of the non browser specific policy, they obviously can not be a part of the "Managed Chrome" offering.
There's no contradiction here; it's totally possible for a company to make a feature configurable so that it doesn't block their competitors but also intentionally design and market it in a way that's misleading in ways that will lead to their competitors getting blocked. When we're talking about a company as large as Google and a product with as much market share as Chrome, I don't think it's that crazy to think that things like this add up to encouraging even more hegemony, and when that happens to align perfectly with the incentives of the company making said product decisions, I also don't think it's crazy to think it's unlikely to be a coincidence.
If the argument is that Google has built a product that encourages use of Google products, of course. The question is whether that's some sort of trickery or odd or bad. "Google offers Managed Chrome as a service" hardly seems controversial to me.