Linkedin used to trick people into thinking you have to pay to see someones profile when you can see it just fine by logging out. That is not against Googles policy. Not sure if they still do that, but I used the logout trick a lot a few years ago.
You sure about that? How big qualifies as big in your eyes? Medium implemented homepage cloaking in November of 2019 and within a month they lost 40% of their overall search visibility:
Pinterest? Google is somehow able to crawl images on their site, but I certainly can't view these images without creating an account and logging in. Their site ranks highly enough that I gave up on google image search last year.
Additionally, off the top of my head Bloomberg and NYT both won't allow me to view more than a few articles but let the Google crawler index their articles.
I've definitely seen article text on Google that was not presented to me when I clicked the link, and not because the article was updated or something, but because I was blocked from seeing the article.
Sounds like an API that will be implemented.