That would require Google to be in the business of knowing every site that you have a membership in.
It is not possible for Google to get access to cookies for other sites, anyway. This is a pretty fundamentally important security restriction that browsers implement to protect you from nefarious sites. So it isn't possible for Google to know which sites you have paid accounts with unless you explicitly tell it.
I did not say that.
I said google could display the results to which you have access, based on your cookies. Assuming they had access to crawl the whole article.