I feel like this is reaching for the vocabulary that you get in mathematics of axioms, postulates, and theorems. Not in a bad way, mind. Just the general idea of building a separate vocabulary for the different aspects of a system of knowledge.

I also think things get complicated with holding things constant as a necessity. Often times, the best way to find a bug is to ask not "how was this possible?" but "why would another part of the system modify this data?"

Obviously, if you can make things reference capable data, you should do so. But, all too often "this data being X" has a somewhat self evident explanation that can help. And just "copy so I don't have to worry about it" lands you squarely in "why is my copy out of date?"