The article makes the following claims about informational interviews for newcomers to the job market:
- they are encouraged as a means of exposing oneself to potential employers;
- hiring managers will not grant them because they lack the time,
- the job seeker's time would be better spent speaking to those who might actually hire her.
Should you present yourself to a hiring manager in any way that discloses that you're actually praying for a job offer rather than information and that exchange will come to a quick conclusion. However, make it transparent that you really want information, that you will consume only the agreed interval of time for the interview, and that you do not want a job from the person you are asking to meet at this time then your odds of success will improve. I won't go into details about how you might do this now. Prod me forcefully in a month or two if I forget.
Which reminds me, why limit your research efforts to 'hiring managers' anyway? Informational interviews are about the entire topic of your career. If you think you might want to be a nurse then ask a nurse what it's like to be a nurse. If you want to know what it's like to be a hiring manager then ask one of them.
When you reach the point where you know you want a specific kind of job in a specific industry in a specific geographic location, when you know what employers expect of people who are seeking jobs like that, and what such jobs pay, and where such a job might lead as part of your own career, and so on—are your there yet?—skip the rest of your career research project for the time being. In other words, if you know everything needed to be able to find and respond well to the appropriate job advertisements, to job offers, and so on then of course there is no need for you to gather information. You have what you need.
When you do need information again—and unless you hate conversation—then the informational interview is one source of information that you can consider. Be prepared for the wonderful possibility that a conversation with someone in a field that you are considering will yield ideas and perspectives that you might never find anywhere else.