

Assuming each user will always encrypt to the same value, this still loses to statistical attacks.
As a simple example, users are e.g. more likely to vote on threads they comment in. With data reaching back far enough, people who exhibit “normal” behavior will be identified with high certainty.
It’s not even only colloquial, it’s the scientific term for it.
Edit: Even things that have nothing to do with machine learning or deep learning are AI. i.e. stupid rule based approaches (aka tons of if-else). Deep Learning is a subset of Machine Learning which is a subset of AI.