According to Japanese website Asahi, Nikon will end camera production in Japan by the end of 2021, all camera production will moved to Thailand. Currently, Z6 & Z7 and Z-mount lens production have already moved to Thailand, and D6 production will be moved to Thailand by the end of 2021.
Translated from Asahi:
At last, Nikon will end the domestic production of camera bodies that has continued for more than 70 years. Until now, body manufacturing has been carried out at “Sendai Nikon” in Miyagi Prefecture and “Nikon Thailand (NTC)” in Thailand, but in order to reduce costs, it will be concentrated at the Thai factory.
Production of the mirrorless cameras Z 7 and Z 6 was completed at the end of September, and preparations for the transfer of production to Thailand have begun in October. Production of the D6 digital SLR will also be transferred to Thailand by the end of 2021.