Whereas Julian May wrote a time travel tetralogy and a future history both set in a single timeline, Stirling wrote a time travel trilogy set in a timeline divergent from that of his Change/Emberverse future history. The Pliocene Exile influences the Intervention whereas the temporally displaced Nantucket cannot influence the Emberverse.
We have come a long way from Volume I of the Nantucket Trilogy to Volume XIV (?) of the Emberverse, Stirling's longest series. We have already been told that the current Black Chamber alternative history is a trilogy.
We look forward to further volumes and series in 2019 and the years ahead when the Earth of our timeline will definitely go through some changes.
