"Before and After" does not erase history, it merely shows it being experienced in an unconventional manner. All the events still have the potential to take place. What might "erase" them is "The Gift," but really those are because of production decisions, not writing.
Kes told Janeway about the Krenim to save her and B'Elanna, which right off the bat erased Linnis's birth from the timeline, and thus Andrew's.