I must clarify my post. I don't believe that this is necessarily a "flip flop" after all. After much mediation on this week's Watchtower study, I think the organization is simply identifying each sexual act within marriage as a conscience decision that will differ from couple to couple.
I don't believe this rescinded any previous "direction", and I still feel that the org will always secretly view "oral", "anal" and the like as "perverse", but now do not want to get involved, undoubtedly for legal reasons.
I apologise for any misinformation I may have spread regarding this footnote, even though it is still a "clarified belief". I now understand it to be a "conscience decision" rather than a permissive attitude towards any sexual activity now.