From the SPARC Open Access Working Group’s statement endorsing the recently ratified UNESCO Open Science recommendation:

The utility of the Recommendation hinges on its uptake by the global community. To this end, we strongly encourage the United States to adopt the Open Science Recommendation in its entirety and work closely with stakeholders to implement it. 

The statement calls out what is among the most important principles in UNESCO’s Recommendation: community-owned infrastructure.

Perhaps in deference to the Open Access Working Group’s diverse membership, the UNESCO document’s anti-APC stance goes unmentioned, nor does it appear in the International Alliance of Research Library Association endorsement statement. Here’s the relevant UNESCO passage:

Ensuring diversity in scholarly communications with adherence to the principles of open, transparent and equitable access and supporting non-commercial publishing models and collaborative publishing models with no article processing charges or book processing charges.