Imagine that the cult decided to stop shunning family members on the proviso that the DFd person was not actively trying to attack the cult.
(Please don't debate whether or not this is likely - it's hypothetical)
How would you respond to your family?
Personally I think I would be less than cooperative. Who needs a conditional relationship that could be taken away again on the whim of seven capricious old men?
I think I would treat my parents as acquaintances, like an aging aunt and uncle who you meet occasionally for polite conversation over tea and scones.