The Crossref board voted in March 2022 to remove the ability for members to limit the distribution of references, to be more in line with all other metadata which is default open.
The REST API had a number of features that supported reference distribution preferences. Since these are no longer relevant, they have been deprecated and removed. This includes the reference-visibility filter, the reference-visibility and public-references fields available via the /members route, and open-references coverage calculations available via the /journals and /members routes.
You can read about the board vote and the membership terms change. All the members that previously had limited or closed references have now been set to open.