Comment by ButlerianJihad

While you're absolutely right, the pronoun "they" is unnecessarily load-bearing here. Most people who are sharing links have no control over the HTML code or HTTP headers, nor are they aware of the Google Search Console.

And you're talking about relieving a symptom on a well-behaved and well-documented public service. Getting indexed by Google indicates that a link has already been crawled, indexed, and scraped by a lot of services, most of which cannot be seen or controlled by ordinary mortals.