Breaking vs. trending Shipped
The trend digest is a ~48-hour sweep. The event brief is same-day, and its whole job is a timing call.
A same-day brief has to be readable in under a minute and has to end in a decision: post now, or wait. Folding that into the trend digest would have produced one command that does neither job well — the sweep is too slow to be breaking and the brief is too narrow to be a digest.