Frankly, I heard different things about that. I myself got F1 and came here as student with no problem (basically officer just stamped my passport without any interview or anything) and my parents got GC year before and were filing for me (and no, I didn't hide the info). In fact I got F1 visa this way twice - 1st time in my country, 2nd time in Canada. However I also heard petition may cause problems to get student visa.