Each of you are correct, there is some existing functionality to add a meta tag to private site. The tag added is `follow‘ />`

However, the existing `robots.txt` rule prevents search engines from reading the meta tag so search engines don’t know they’re not supposed to index the site. This is like writing “to be opened by addressee only” inside an envelope.

Removing the `robots.txt` rule in WordPress 5.3 will allow search engines to read the meta tag. The second directive of the meta tag has been changed to `nofollow` on private sites to prevent unnecessary crawling.