You need to pass the string, updateLabel, to a string property you create in DropPinVC, and have that controller populate its label in viewDidLoad. Your approach doesn't work because the view hasn't loaded yet at the time you try to set the label's text, so myVC2.TypeLabel will be nil.
Also, you're not using your property, myVC2 in TypeLocation. this line,
DropPinVC *myVC2 = [[DropPinVC alloc] initWithNibName:@"DropPinVC" bundle:nil];
should be,
self.myVC2 = [[DropPinVC alloc] initWithNibName:@"DropPinVC" bundle:nil];