This feature is experimental. Please share your experiences so we know what to keep or change.
Whether the previewed render pass is a revalidation an expired cache entry.
Cache revalidation is only previewed when an [up-revalidate-preview] attribute is set or when a { revalidatePreview: true } render option is passed.
[up-revalidate-preview]
{ revalidatePreview: true }
When revalidating, the preview will be called after the expired content has been rendered from the cache.
