It looks like Google is migrating Google Search Console from /webmasters to /search-console in the near future. Remember, Google rebranded Google Webmaster Tools as Google Search Console almost exactly a year ago. Since then, Google kept the URL /webmasters over the past year. But now I guess Google is in the process of migrating it to /search-console.
When I try to access certain features at search.google.com/search-console/ I am redirected to search.google.com/search-console/unavailable which says “Coming soon!” “Thanks for trying Search Console’s new Mobile-Friendly Test! We are gradually rolling this feature out; please try again in a few days!”