I-485 and F1 status

After applying for AOS, whether the F1 status is valid is a really controversial--lots of discussion everywhere. however, I heard several cases that the students hold TA/RA position even after ting I-485. Some of them even consulted local immigration offices and got positve answer. Anybody or anybody heard someone could not go back to F1 when I-485 is denied.

Another concern is what the chance or reason of denial for I-485? My case is employmend-based.


thanks a lot for your input.