Quite interesting. So both 165 turbos and 1502 gwr to wolverton.
The aborted DA3 franchise did see all but 10 sets removed in favour of a strengthened 'Turbo' fleet - presumably the remaining 10 would have been confined to the Cornish branch lines. There is currently a programme of overhauls (not the C6s the Angel sets 202/216 are programmed in for) which will see costly wheelset overhauls - I suspect these will be the last in their GWR lives.
It was said elsewhere a long time ago that 150202/207/216 were going to be having some money spent on them at some point so whether that will be them having their interiors redone we will just have to wait and see...
Given they've had their interiors refreshed already I seriously doubt that the seats are about to replaced.
You could say the same about the 143s though, which had many of their seat covers replaced replaced before retirement from service. Of which, ironically, some are now in 207 (which hasn’t been refreshed) and now contributes to the mishmash of FNW, Northern and GWR interiors.
Replacing life-expired seat covers is one thing - changing two units worth of seat fittings is quite another! Never say never, but it would seem like money for old rope in an era where every penny counts.
143s had 2+2 seating, Chapman seats which tend to be preferred to Ashbournes, and larger windows which make them less cramped. Also, 150s tend to end up on Plymouth Penzances fairly often these days which is a longer journey than 143s made.