Adding /** @var $people Person[] */ does not seem to make a difference when I type $person->.
What I see in both cases (with and without the 'comment'):
I have to type > as well, while in previous cases this was automatically added.
Then I see a popup dialog with getAge, getName, setAge, setName.
So, in both cases I see completion (at least in the way I understand it).
F1 also works in both cases.