So many things could have happened to them over the past 7.5 years, best to just keep them unknown. Anna, Mikey, Kent were different - Alexandria getting firebombed made them likely victims. Craig and Crystal were likely victims of the tainted weapons attack on Hilltop. But these folks you mentioned, not entirely clear. Who knows, they may be back. Frankie was missing but showed up in 9x14 and 9x15.