Observed history compares the complete announcement, including corrections and reordered passages. When Microsoft edits a passage, ChangeIntel keeps its earlier citation and records the new wording separately; it does not guess that similar text describes the same API change.
Compatibility and schedule labels are text-based review signals, not Microsoft's structured assessments. An absent label does not establish compatibility or absence of a deadline.
The publisher supplies a month; day one is only a sorting bucket. History starts when this installation first records the group; earlier changes may be missing.