The Type I (AU/NZ) plug is different to the Type I (China) plug. For one thing, the Chinese one is upside down (or maybe the AU one is?) but the biggest difference is the AU standard requires the active and neutral conductors to have insulation over half of the conductor (presumably to prevent a kid with a butter knife or paper-clip touching the hot conductor on a half-inserted plug). The Chinese one has no such protection (also, generally seem to have holes on the pins). So while they may be inter-operable, they're not necessarily legal or safe (for example, the Argentinian Type I apparently swaps active and neutral). In the same way that a Euro (Type E) plug can fit in a UK (Type G) socket if you can push Earth door open (useful not just for travelling Europe, but also Asia, where Indonesia uses E, but Malaysia uses G. But you really shouldn't do that).

I'm curious why American Samoa uses Type I (among 3 others) but on 60Hz/110V...

Also, some of the voltages are wrong; AU is listed as 230V, but the situation varies between states, and between nominal and actual.

In short; Wikipedia has more detail and accuracy.