>that should come out-of-band of the code in question.
Ideally, yes. After a decade and something' under ZIRP, seems a lot of workers never had incentive to remain conscious of their intents in context long enough to conduct productive discourse about them. Half of the people I've worked with would feel slighted not by the bitterness the previous sentence, but by its length.
There's an impedance mismatch between what actually works, and what we're expected to expect to work. That's another immediate observation which people to painfully syntaxerror much more frequently than it causes them to actually clarify context and intent.
In that case the codebase remains the canonical representation of the context and intent of all contributors, even when they're not at their best, and honestly what's so bad about that? Maybe communicating them in-band instead of out-of-band might be a degraded experience. But when out-of-band can't be established, what else is there to do?
I'd be happy to see tools that facilitate this sort of communication through code. GitHub for example is in perfect position to do something like that and they don't. Git + PRs + Projects implement the exact opposite information flow, the one whose failure modes people these days do whole conference talks about.