I'm not so sure, Ken.
Reims and Chartres roofs were both rebuilt after fire with iron and concrete trusses, and they could be "justified" in this case as well. See my blog post on this topic for pictures..
"...is faithful to the "last known visual state" of the building" may mean the exterior forms and not the structure that few ever see.
I would be thrilled to see the roof timber framed, of course.