How long it takes to update a case from F2B to F1 after my parents notifies NVC of their citizenship? My priority date for F2B is june 2005 and if they upadate i should be moved to F1 where the current PD is december 2005 (which means my priority date is more than current). How long it might take for me to get an interview
If you send them a scanned copy by e-mail to NVCinquiry@state.gov, they will update it immediately. You will soon get a notice stating your case is being forwarded to the Consulate in your country of origin, and then your country's consulate will schedule you an interview based on their availability (if I had to guess, I'd say an appt. for February would be a long shot, maybe March).
You need to scan a copy of their naturalization certificate to the NVC already graciously provided by the other colleague. NVC is pretty quick. A few weeks perhaps. In order to determine when your PD will become current, whether F-1 or F-2B will also depend on your native country of origin. Good luck.
Make sure when you informed them, you sent the letter through something you can track (priority mail, fedex etc.). Then it's important to keep following up, whether through infopass or calling the CIS hotline number. The answer to "how long they update" the category is that the CIS in very inconsistent in these requests. Unlike a filing (I-130, 485 etc.) If these requests are not followed up on, they sometimes do not even update it, because you won't get some sort of receipt notice when you send these requests.
That said if the category was switched and the priority date is current, the petitioner would be notified immediately and the interview could range anywhere between 3 to 9 months to even a year depending on the country and consular office's schedule.