Incompatible with decentralization. We disagree with the assumption made: in our experience with GLAM, all of the partners were able to find us.
We don't believe that bigger partners interested on Wikipedia are unable to find WMF or any other affiliate. To contact with WMF should be as easy as sending an e-mail. The main website of Wikimedia Foundation has a section clearly visible to contact them with a business@ e-mail account. We can't believe that a new entity (with budget and staff) should be created to receive an e-mail.
If that wasn't the proposal, please, redo the text. We'll be glad to read it.