Google has added new guidance to the "Fix Search-related JavaScript problems" help document, specifically addressing JavaScript-based paywalls.
This is currently listed as number 10 here, and says:
If you're using a JavaScript-based paywall, consider the implementation.Some JavaScript paywall solutions include the full content in the server response, then use JavaScript to hide it until subscription status is confirmed. This isn't a reliable way to limit access to the content. Make sure your paywall only provides the full content once the subscription status is confirmed.
This is standard SEO JavaScript advice, but it has been explicitly added for paywalled content.
Google explained this content was added to "help sites understand challenges with the JavaScript-based paywall design pattern, as it makes it difficult for Google to automatically determine which content is paywalled and which isn't."
Here is the section that was added:
Forum discussion at X.
