The article you posted doesn't mention "offline" at all. We use SQLite as a cache in the browser when available and in iOS/Android/desktop apps, but we didn't have any guarantee that a page you want offline is actually available offline.
It would "mostly work" offline before, but you could have cases where some blocks in a page aged out of the LRU, or they changed online in a way that invalidated the page but new content wasn't downloaded. When that happens we show a "go online to view" error instead of risking you viewing/editing a known-incorrect local snapshot of the page.
With "available offline", we now proactively download and keep up-to-date the content you want available offline. It will either work, or show an explicit error if things go wrong in the sync process. No more guesswork.
It would "mostly work" offline before, but you could have cases where some blocks in a page aged out of the LRU, or they changed online in a way that invalidated the page but new content wasn't downloaded. When that happens we show a "go online to view" error instead of risking you viewing/editing a known-incorrect local snapshot of the page.
With "available offline", we now proactively download and keep up-to-date the content you want available offline. It will either work, or show an explicit error if things go wrong in the sync process. No more guesswork.