Noticed this on a couple of sites - not sure if this is a bug yet. When I tested on dmaster it fills correctly so perhaps this is a bug/regression that has been fixed between 4.7.27 and 4.7.30/31
This is a CiviCRM Core bug, reported here: https://lab.civicrm.org/dev/core/issues/173
It applies to pay later contributions when the email address is included in the profile.
I see this too. I believe its only when the pay later is enabled and the donor selects pay later. The email addresss is not shown. A simple hack may be to find the code change it to just "has been sent." until someone with more knowledge than me can fix the problem. I tried it with a 4.6.X version (on Joomla) and the email showed properly. I tried it with a 4.7.X (on Wordpress, I forget which version I was at! 32?) and had the problem. So I upgraded that to 5.0.2 and still have the problem.