The whole reason for the existence of PLCs, as opposed to other computer systems, was the concept of representing Boolean logic via elements of electrical circuits: contacts, relays, timers and counters. This is what made the PLCs so ubiquitous: making programming understood by electricians. Structured text and other more advanced methods appeared later, with the goal of overcoming the obvious shortcomings of Ladder approach.
Therefore, when explaining PLCs, one cannot skip the ladder representation even if it is not meant to be used in the future. And in the electrical world terms "normally open" and "normally closed", NO and NC, have existed for more than hundred years and have become de-facto standard understood by everyone. I think any deviation from them even when describing a bit in memory rather than a physical contact will just muddy the waters. Do not overthink it.