Or do you class the IFE as different between J and WT+/WT?
So the same content on different screens would not, IMHO, be 'the same IFE', but rather 'same IFE content', as the IFE experience would vary depending on the screen size, contrast etc..
I did answer your question, see above, but for the sake of pedantry, yes, I class the IFE as different between different classes. The screen size/resolution makes a huge difference to the experience.
I can't see how a reasonable person would consider a movie on those tiny old 1990s technology First screens to be 'the same IFE' as watching the same film on the CW screen, which are much larger.
However, everyone is entitled to their opinion.