Well, it only took six days for Google to “fix” their de-indexing bug. According to reports, they have not elaborated on what caused the issue.
The indexing issue has now been fully resolved. We apologize for the inconvenience. We appreciate your patience as we restored normal operation.— Google SearchLiaison (@searchliaison) April 11, 2019
What happened during the de-indexing issue in Google?
Google randomly dropped various websites out of its index for no apparent reason. The drops likely caused significant loss in traffic / revenue to websites affected.
During the de-indexing issue, we quickly found that ‘re-fetching’ the page resulted in the site to be re-inserted into Google’s index.