To answer the OP: Its simply a matter of Evolution in a very general non-scientific definition/sense of things changing over time vss Biological Evolution, which is a very specific type of change. I think the society supports the former, not the latter.
Also, a comment on the above 82 Watchtower: This is completely absurd and shows the true nature of the two-class system. Anointed and Other sheep ARE NOT equal in JW theology as they like to claim (as in both righteous but have different destinies). If the heavenly resurrection is to perfection, why not the earthly resurrection? Both have dies and paid for their sins, so why does God create a new imperfect body instead of a perfect one, like he does for spirit bodies? Why do the great crowd have to work towards perfection for a 1000 years while the anointed achieve perfection instantly!?