Sonar 2087 has been upgraded recently, as its removed from T23 it will transfer to T26. 3 additional sets were purchased to cover the first 3 T26 in build so that transfers would not be necessary, after that all units would be transferred. An additional purchase of S2087 will have to happen to cover the additional Norwegian T26.
For S2150, again there was a recent upgrade programme of the seagoing sets, of which there are 13 in total. Obviously 8 are reserved to T26, suspect the 5 additional will now just go in the Norwegian T26.
Artisan are transfers as well, but it has had a refresh, ultimately T26 will probably get a new 'Artisan V' set eventually based on BAE's NGTRM architecture.
https://www.navylookout.com/the-royal-navys-next-generation-radars/