No, I do not think a slow fade is selfish when you have kids. It all depends on the circumstances. In my case, it's the opposite of selfish. The kids have had good relationships with their extended JW family which, due to a few bereavements over the years, has become considerably smaller. These connections have been precious and it would have been cruel to rip those apart or create MORE disfunction by causing a scene over our problems with the religion.
While they've been growing, we've made sure they've had a watered-down JW experience - quietly 'celebrating' their birthdays, taking some Sundays to have a picnic in the park instead of going to the meeting, giving them interesting things to do during the meetings, pursuing their interests and talents, homework or early nights coming before meeting attendance, not active in the TMS, never becoming publishers in their own right, sleepovers with their school friends, participating in as much as possible at school, contact with DF-ed relatives, etc. - and they have become aware of some of our difficulties or ambiguities with JW teachings and the position we, as a family, are in. As the kids get older and become more independent, they'll be able to maintain (or otherwise) their own extended family relationships irrespective of what happens to us. They will remain free. That's been the plan anyway.
Having said that, we are aware that due to our balancing act, a heavy burden has also been placed on their young shoulders. They too have had to learn how to live in two worlds - what to say and not say in front of whom. School can be very hard - there are other JW kids there too - it can be a logistical nightmare dealing with the conflicts of interest, and a cause of great stress at certain times of year.
Only time will tell whether we made the right call or not and to what extent we've screwed them up!