Not sure if the exact API calls will be added to KSDK_v2 in the future or not. But you can get access to the data with what is present in KSDK_v2. I modified the hello_world example for frdm-k64f Freedom board as follows:
PRINTF("hello world.\r\n");
#if 1 //DES 1=test (access to SIM registers), 0=default code
{
uint32_t my_sim_sdid, FamilyID, SubFamilyID, SeriesID, RevID, DieID, FamID, PinID;
SIM_Type *my_sim_ptr = (SIM_Type*)(SIM_BASE);
my_sim_sdid = my_sim_ptr->SDID;
FamilyID = SIM_SDID_FAMILYID_MASK&(my_sim_sdid);
SubFamilyID = SIM_SDID_SUBFAMID_MASK&(my_sim_sdid);
SeriesID = SIM_SDID_SERIESID_MASK&(my_sim_sdid);
RevID = SIM_SDID_REVID_MASK&(my_sim_sdid);
DieID = SIM_SDID_DIEID_MASK&(my_sim_sdid);
FamID = SIM_SDID_FAMID_MASK&(my_sim_sdid);
PinID = SIM_SDID_PINID_MASK&(my_sim_sdid);
#if 1 //DES 1=change output format, 0=default code
FamilyID >>= SIM_SDID_FAMILYID_SHIFT;
SubFamilyID >>= SIM_SDID_SUBFAMID_SHIFT;
SeriesID >>= SIM_SDID_SERIESID_SHIFT;
RevID >>= SIM_SDID_REVID_SHIFT;
DieID >>= SIM_SDID_DIEID_SHIFT;
FamID >>= SIM_SDID_FAMID_SHIFT;
PinID >>= SIM_SDID_PINID_SHIFT;
#endif
PRINTF("\n FamilyID = %x\n SubFamilyID = %x\n SeriesFamilyID = %x\n RevID = %x\n DieID = %x\n FamID = %x\n PinID = %x",\
FamilyID, SubFamilyID, SeriesID, RevID, DieID, FamID, PinID);
}
#endif