The gates do not detect any new issue caused by changes elsewhere. E.g.
“Unread “private” fields should be removed” is not detected on new code if the accessing code is removed.
The gates seems to trigger on any issue with a line of code that was touched, even if it is an old issue.
This can be considered good, in that it encourages fixing issues in code you touch, but it is sometimes very annoying when refactoring legacy code e.g. by improving a name or reformatting the code. A simple rename or reformat can activate lots of old issues on “new code” and thereby discourage refactoring.