I'm just a premed like you, so take this with a grain of salt, but my understanding is no, they are technically very different. LCME requires them to go in strict order if the list is ranked, so most don't do that, because they want the flexibility to replace a female with a female, URM with URM, etc. So, they get around this by creating unranked tiers, which gives them the flexibility to jump around within the tier as they see fit. This is actually what most schools do, whether or not they communicate the tier to us.
By the way, if a list is ranked, LOIs, updates, etc. cannot, by definition, have an impact, since your decision is already made, and you are just waiting to see whether or not they get around to you. Another reason ranked lists are not really in anyone's best interest.