There have already been several N5 rumors. Sure, maybe not as many as the N4, but maybe, Google's just improving at hiding what they're doing. Plus, there's no evidence or reason to not make an N5.
I know, but they are only rumors. And I agree, It would be dumb not to make another Nexus considering the following it has accumulated.
So I guess your are right, They have gotten better at hiding things, and testers are not allowed in bars anymore. HAHA