TK has only adjusted their schedule until 27 March 2021.
For 28 March 2021 and onwards, the schedule is a placeholder so TK might zero out those flights in the near future and cancel them.

Also, there is a possibility that the flights are full; the seat maps are not an indicator of the exact loads as not everyone is choosing seats and it could be some travel agents creating dummy reservations to hold availability for their own customers.