navigator.cookieEnabled currently indicates if “the user agent attempts to handle cookies” in a given context. A change in Chrome, shipping as part of third-party cookie deprecation (3PCD), would cause it to indicate whether unpartitioned cookie access is possible (causing it to return false in most cross-site iframes). We should restore the prior behavior of navigator.cookieEnabled which indicated only if cookies were enabled/disabled for the site and rely on the cross-vendor function document.hasStorageAccess to indicate if unpartitioned cookie access is possible.
Divergence in the meaning of navigator.cookieEnabled will cause confusion as Chrome rolls out 3PCD. We have a window, before 3PCD ships, to restore prior behavior now that there is some amount of consensus between browser vendors on what navigator.cookieEnabled should indicate in third-party contexts.