we (whole family) had an interview on 10/23/15 in LA office. he looked at all our i-94s and later got all the originals (asking us if we made copies for ourselves). he asked the kids what their birthdays are, confirming their identity. asked for the latest EVL. in the end he said that he would have approved it but there were no visa available as the bulletin retrogressed. he said that we would need another medicals but some colleagues advised to hold off on it because they don't know when our priority date will be current again. if it's not within 6 months, the medicals that he just requested will be expired again and then we'll have to do out all over again, making us spend more money. He said that that he cannot keep our file so we are to expect that it will be transferred again where it will wait for the dates to be current again and this new office will be the one to request for new medicals (when it becomes ready for us).
Our dates became current in March and I have made 2 e-requests already. no progress so far.