Should I hide content when developing a new site?

Question

Search Engine Optimization

I am redesigning the site, I am creating it from scratch on a test domain. I transfer all the content of the old site by hand to the new site. The old site still works. Can problems arise due to the same content on different domains in my case? The test domain was not promoted.

Answer 1

Can problems arise due to the same content on different domains in my case? The test domain was not promoted

They can. And if bots have access, then it is quite real. No robots and disol / noindexes can help. Install the maintenance
plugin , use a non-existent domain ( hosts ) or password-protect the domain directory.

Answer 2

The site on WP, in the reading settings, checked the box "Ask search engines not to index the site", and also threw robot.txt into the root and inside the propsial
User-agent: *
Disallow: /
Looked at statistics on Yandex and Google. Robots indexed 12 and 13 pages of the site (((How to be in this case?