I find that a lot of well-meaning tools (e.g. bazel) regard non-error output as noise to be hidden. They'll often route any messages like this to the nearest wastebin they can find, which makes logging incredibly unreliable as a means of communicating constraints in some domains.
I'm thinking the log message is something you wouldn't want to trigger in production anyway, unless you're pretty confident that it won't lead to a ton of spam on the day that inputs rise over the threshold.
Using a debug log-level helps prevent that problem from occurring in production, while still making it visible to developers that have more logging enabled in their dev/test environments.
