Columns dropped from your source now leave the ontology
A DDL upload now removes columns that are gone from your source, the way a warehouse schema sync already did — so projects that upload DDL stop carrying columns the source no longer has, and the assistant stops being offered them. Only bare columns go quietly: anything a join, metric or virtual table uses, or that you have described, still waits in Review. An upload that keeps every table but drops a quarter or more of their columns raises the same “this file looks incomplete” warning a mass table removal does.
A rejected upload now names its reason: a DDL file cut off part-way through says so.