Markdown file previews with user mentions works wrong

We noticed new update on the interface. Markdown preview now show links to users, if your text has structures like "@sometext".
It's really confusing, because we see some strange users, which we don't know, which never joined private repository.

Original source:
http://prntscr.com/jdkd18\\
Preview:
http://prntscr.com/jdkdb7

Because of NDA we can't print full usernames, so we use just 2 letters of first/last name. And they do not correspond any real users. But now this new preview confuse all our company members, who use git.

• I wrote to support already and they answered, that I should raise a ticket here.