In a live stream program The Natsume Yuujinchou: Saikai no Tayori it was announced that two Natsume Yuujinchou new episodes will be released for the series in the upcoming Spring season in 2021. The episodes will premiere in theatres in 2021.
The studio will be Shuka Studios the same studio that adapted the fifth and sixth season in 2016 and 2017 and the movie ‘Natsume Yuujinchou: Utsusemi ni Musubu’ released in Japan in 2018.
Natsume Yuujinchou 2021 Official Announcement
There is a official website and twitter account also for the anime. You can also check out for future updates there.