If there are fewer bits of weights than original data, and the weights + an algorithm can be used to reproduce the original data (even lossily), then it's absol

If there are fewer bits of weights than original data, and the weights + an algorithm can be used to reproduce the original data (even lossily), then it's absolutely a compression in the information theory sense. The degree of lossyness needed before it's not considered a copyright violation is what humans determine case-by-case in court, but that doesn't make it any less of a "compression". Just like your neurons "compressing" the gazillions of atoms in the world you experience down to smaller representative models in your head.