This is just a thought - I can't back it up with evidence and it's based on my assumptions and experience.
WTBTS seems to be putting a lot of effort into their work in developing countries where (this is a generalisation) there tend to be less-developed critical thinking skills and less of a tendency to question those who appear to be in a position of authority. In some of those countries (e.g. those in SE Asia) the sort of thinking shown in the articles about 'serving the husband' and so on would be much more acceptable than in the more liberated 'western' countries.
When I was living in Cyprus I observed that those dubs who employed Filipina 'housemaids' tended to take them to meetings and there were quite a number of Bible Studies going on with SEA ladies. My dub friends were very keen to bring Tagalog magazines to my (now estranged) wife. She - although an educated woman - was not discerning enough to recognise any difference between the dubs and the religion in which she had been brought up (Methodist) and any 'Christian' religion was all the same to her, as it was to many of her friends.
Had I been religious she would have followed me into a religion without a second thought. (The mags went into the bin).
As for the other part of it, her ostensible mission in life was to make and keep her husband happy and I believe from my experience with other SEA ladies that this is a cultural thing. And in my experience any prohibitions/limitations as to sex life would not be easily accepted.
Just my thoughts.