Google is sunsetting the preferred domain setting in Search Console that allowed site owners to specify which URL to display in search results.
Along with the deprecation of this setting, Google will no longer use any existing Search Console preferred domain configuration.
The preferred domain setting was one of many ways of signalling to Google which version of a URL should be picked up as the canonical for search.
Google notes that there are many other options available, such as:
- Use rel=”canonical” link tag on HTML pages
- Use rel=”canonical” HTTP header
- Use a sitemap
- Use 301 redirects for retired URLs
Even without doing any of the above, Google will still do its best to figure out the canonical URL on its own.