At one time, those tests didn't include POS, comfort/service animals, or families with infants, either.

I agree, the tests should take into account cabin baggage, at least underseat items. It's all well and good to talk about what people should do in an emergency - stay calm, no pushing/shoving, follow crew instructions, etc. - but you've also got to be realistic. In a panic situation, people are going to do what they're going to do.

I think it's also worth noting that 85% of pax fly once a year or less. Unlike (possibly) experienced flyers, they won't have separated their belongings out so they have a small, immediately accessible emergency bag close at hand at all times. Their instinct will understandably be to grab their belongings.