I (like many) use the site:domainname.com search operator for a simple way of getting an idea of a sites index count to track down any technical issues. This would include domain migrations when moving from one site to another.
I had a client send me a screenshot using the site:domainname.com search operator showing that their old domain was being indexed by Google – like in the screenshot above.
My initial thought was: “holy shit, this ain’t good”. Because that site doesn’t exist anymore, we needed to reverify Google Search Console by adding a DNS record to investigate further.
Once we got access, I reviewed all URL versions to make sure traffic wasn’t flowing in from a redirection issue and to make sure the Coverage reports were in check.
I was stumped – the redirect was being read correctly as a 301, and there were no issues within GSC.
And why was the Title Tag and Meta Description being used on the old site when checking for the indexed pages?
I then did some tests on other sites that I knew had a domain name change at some point in time and there was a similar result.
Good to know that there isn’t necessarily a technical issue on your end if you’re seeing this, although it’s most likely something that Google has changed.
I’ve reached out to Google to get confirmation on this although haven’t heard back as of yet.