http://www.southasia.com.au/2015/06/16/nepalese-granted-temporary-protection-status-in-us/

When the TPS is terminated by the US government, the immigration status of the concerned Nepalese nationals shall revert back to the status they held before the protection was granted.

Not sure, if F1 apply TPS, granted, TPS ended, can they are reverted to F1.