You would think though if it was related to your status they would ask you to bring original documents of your work visa and your approval for asylum right?? I have no idea what would require no documentation at all...
Not to beat a dead horse, but if had your GCMS notes it would state why they are calling you for interview. Not saying you
have to do it to prepare (given that you already feel prepared for any questions they might have), just saying you'd get a sure answer from it... though if you did order them at this point, apparently they can take up to a month to arrive, so your interview might happen before they arrived ^^;
In any case, as far as I can tell from what you've posted on this forum, seems like most everything your case has been unusual in processing so far... so I am very curious about your developments! Hope you get a positive decision at the interview