I suggest waiting till FDR and CVR are read out, in order to have at least some idea of what actually happened.
However with EGPWS installed (and operational) then this type of event should not occur.
While we don't know yet what actually happened, and what was the equipment level of the crashed aircraft, it is true that the EGPWS will start shouting TERRAIN, TERRAIN! PULL UP! much earlier than ye olde GPWS. However, you still need to have some power reserve to climb and 42-300's climb performance is mighty dismal. Again, this might or might not have anything to do with the crash.
Merida is a VFR airport
ASN reports clouds half an hour before departure to be SCT013 and that turned to BKN013 half an hour after departure. Dunno 'bout mountain flying in Venezuela but on the plains where my homebase is located this is no VMC.