While I think this is true, there's also some benefit to getting the manufacturer's to pay lip-service to the idea.
In that, it becomes part of the marketing and the sales of the device. Later, consumers can _attempt_ to hold manufacturer's feet to the fire with false advertising and other fraud class action lawsuits.
It's really really not a good system, but even forcing a bit of lip-service is a marginal improvement over what we have now.
> Therefore, the most meaningful step would be to require support for open-source firmware.
I agree that it would absolutely be better, but it sounds like even this voluntary labeling program is the compromise that might be tolerated by the other members of the FCC. I'm guessing such a strong and effective program would be a non-starter with those members.
Which, honestly, tells me a lot about the other members of the FCC, and whose interests they are seeking to serve.