In addition to info on the world book, Harriet revealed some more details generally about the series:
The series is finished and done. Tor offered a lot of money and tried to persuade Harriet into doing more, but Harriet put her foot down and said no. The Wheel of Time ends with A Memory of Light and the companion volume.
There were several unfulfilled contracts when Robert Jordan passed away, including for the Seanchan trilogy. Apparently the money involved was massive, worth many times the value of Harriet’s house. Tor worked with the estate to re-write the contracts to substitute the companion book instead.
Robert Jordan wrote one line about the planned Seanchan trilogy: Mat Cauthon playing dice in a grubby alleyway in Ebou Dar (not verbatim). That was it.
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