That’s redundant. It’s obvious this is an opinion piece. And they’re not wrong either.
"We believe that everyone is an expert based on their own lived experience, and that we all have unique and brilliant contributions to bring to a design process."
Not that they're practicing what they preach anyway - there's only one voice that matters and that's the OSI's Executive Director (https://discuss.opensource.org/t/proposal-to-achieve-consens...):
"We see the role of the designer as a facilitator rather than an expert."
The guy has an interest in the definition failing. If it doesn't he won't be able to market his AI as Open Source.