Google is testing, I think again, showing a Google phone number, instead of the actual business’s real phone number, in the business local listing in Google Search. In this example, Google is showing both numbers actually but lists the Google number first.
Google is telling searches that “Google Numbers help businesses provide better customer service by allowing merchants to se their call history.” The Google My Business call history is from 2020 but rolling out more broadly now.
Here is a screenshot from the Local Search Forum:
Joy Hawkins wrote there “From what we found, I think only devices/IPs that Google knows manage the business listing would be able to see it. I also think you have to be in the USA and it’s only on mobile-Chrome. One of my colleagues was able to trigger this on another listing that he manages that has the call tracking feature enabled (but not your example).”
I could not replicate this either by the way.
Forum discussion at Local Search Forum.