Internal domains generally resolve to private IP ranges, so don't do any harm when broadcasted. Besides, many people use Chrome, and who knows what they do by default with browsing history.
Leaking internal hostnames could allow an attacker to build a view of an internal network ahead of time, before actual penetration. Once inside a network it's often a race against time, so this can make a difference.
Chrome don’t actively publish nslookups on public sites.
I think you’ve missed the point.