I'm seeing the same issue in the latest EAP release.  Here's a simple code snippet:

    $row = new static();

    $row->fromJson($json);

    return $row;

If I change that first line to:

    $row = new self();

PhpStorm stops complaining.

I know that, that's why I'm using static and not self.  However, since the method is part of the parent class, the method should still be valid when the new static() is called from a derived class.  So, shouldn't the code checker recognize the $row variable as an instance of the current class and show the method as reachable?