Nope...
.... it does not carry ANY expectation or requirement of you to bring and disribute fish extender gifts IF you have a fish extender to hang out. The first time we did this we had NO IDEA of what to expect.
We signed up for our last
DCL voyag inside of the pay in full deadline - and we ordered our fish extender in that limited time frame. SO there was precious little time to dream up how to fully join the fun. We did attempt to participate as contributors though in having what we felt were nicer than normal gifts for all of the children in our DIS group - which resulted in some 80 kids total.
SO, if I had only kids gifts - and nothing for adults or every cabin (I vaguely recall there were about 115 on our last voyage).... then certainly on every voyage there are participants who will bring nothing and simply enjoy the fun.
As such, I would encourage each of your family's cabins to particiapte. Believe me - just receiving is perfectly fine. IF you want to bring stuff to distribute then it can require large numbers of your gift/item... and it can consume huge time to walk the entire ship distributing them! It took me some 2.5 evenings to do it all... as I pushed a stroller so I wouldn't have to carry my suff around - and I did it strictly late nite in the company of a DIS neighbor ...
LetsGoSteelers.
So you don't want to undertake bringing stuff to distribute litely. I am not sure yet - but I am thinking of bringing something for every cabin too. the only thing that makes me hesitate is the idea of spendign another 2-3 hours walking every deck to distribute these. Trust me - in a prior life I was NO Mailman!