What I meant is that git doesn't have any structure to represent an edge other than a simple pointer. Conceptually it wouldn't be a big change to add some, but the consequence of that is that everything in git revolves around nodes rather than edges, and whenever the concept of an edge is needed (such as in "cherry-pick") it's being calculated on fly.
I don’t see where this would be causing any issues. There is a canonical place where to put edge metadata, namely in the child commit. And whenever you’re interested in move information, you have to process the respective child commit anyway.
If you think of it not as a "rename" (which would belong in the edge object if it existed) but rather as a "note: the file A in this tree was known as B in the parent tree" it would make perfect sense to store it in the child commit.