No. They do not have to maintain any status while I-485 is pending. They could stop taking classes or whatever. They could also choose to maintain status if they want.
it's on your own risk but most of the AOS cases are adjudicated with success. In the rare cases it gets denied then keeping F1 status would protect you from deportation proceedings.
AOS doesn't give you "status". But "status" doesn't really have that much significance. But you are authorized to stay in the US when AOS is pending regardless of whether you have status, i.e. you won't be deported for being out of status. Also, regardless of whether AOS is approved or denied, the period when a timely-filed AOS is pending is not counted towards "unlawful presence" for the purposes of the unlawful presence ban; however, that's not really important in your case because as an F1 student who was admitted for "D/S", there is no date on your I-94 for you to stay past, so you don't automatically accrue "unlawful presence" anyway. (Being "out of status" does not trigger "unlawful presence".)Thanks, although we don't foresee any issues with the AOS adjudication , just that fact that there will be a cancellation noted on SEVIS is bit disconcerting. So if for any reason 485 doesn't get adjudicated, USCIS won't consider the AOS waiting period as legal status?
AOS doesn't give you "status". But "status" doesn't really have that much significance. But you are authorized to stay in the US when AOS is pending regardless of whether you have status, i.e. you won't be deported for being out of status. Also, regardless of whether AOS is approved or denied, the period when a timely-filed AOS is pending is not counted towards "unlawful presence" for the purposes of the unlawful presence ban; however, that's not really important in your case because as an F1 student who was admitted for "D/S", there is no date on your I-94 for you to stay past, so you don't automatically accrue "unlawful presence" anyway. (Being "out of status" does not trigger "unlawful presence".)