it all depends on second hand mac component prices.
from my knowledge apple changes the casing and motherboard for almost every mac hardware update. thus making components more expensive (lower runs) and the re-sell value high.
so for apple to allow replacing parts the backlash from a reduced re-sell price would need to be lower than the potential new avenues of 3rd party components and repairs.
No, the resale value isn't high because they are difficult to repair. It would be the other way around.
Currently, I wouldn't pay much for any Mac with a butterfly keyboard, as Apple only warrants it for 4 years and after that the machine is totalled.
