Google posted on Twitter that as of December 15, the Index Coverage report in Google Search Console is more accurate. Specifically, it is more accurate in reporting on indexed pages.
Google’s Statement. Google said “From Dec 15, the Index Coverage report can more accurately report on indexed pages. Because of this, some pages that were ‘Crawled – currently not indexed’ are now known to be indexed. You’ll see a chart notification in this report.”
The chart with notification. Here is a screenshot of the chart with that indicator on December 15:
More indexed pages. This means that despite what Google has been reporting with pages not being indexed, when labeled as “Crawled – currently not indexed,” some of those pages were indeed indexed. Here are more screenshots from the SEO community showing this:
Why we care. Pages you may have thought were not indexed, may have, in fact, been indexed. Often indexed page ratios are an important metric SEOs and publishers use to determine the health of a web site in Google’s index. This update may show your site to be healthier in Google than you originally believed.