It seems to me that the positions labelled “definite” vs “indefinite” here are really closer to “self-determination” vs “fatalism”. It may be true that at the scale of societies these are highly predictive of each other, but I’m not sure that they are really interchangeable.
In particular the coin toss society thought experiment wasn’t convincing to me at all.
Despite the form, statement (b) is not actually a logical conjunction. It is a statement about the collective of both parents.
This becomes clearer if we strengthen the statement slightly to “Alvin’s mother and father are responsible for all of his genome”. It’s much more clear now that it is not a logical conjunction. If it were, it would mean “Alvin’s mother is responsible for all of his genome and Alvin’s father is responsible for all of his genome”, both of which are false.
My strong expectation is that in Life, there is no configuration that you can put in the starting area that is robust against randomly initializing the larger area.
There are very likely other cellular automata which do support arbitrary computation, but which are much less fragile versus evolution of randomly initialized spaces nearby.