I do not see any problems.
In the FP notice that I got its says If in case I cannot make it on the date mentioned, I could go in on same day of the week on any week following that. But it has a validity date which I do not remember correctly. But it was about 3 months(not sure) from the scheduled date.After that date it says the i 485 application would be considered as abandoned. But if you could inform INS and reschedule the FP, then it should be fine. But defenitely the processing would be delayed by a few months.
