This sounds like a very reasonable idea, actually. My parents gave us books on puberty to read when we were about three or four years old, and we've done the same with our children. I suspect that, for younger children, the information is reassuringly objective, absent the tabu element for pre-teens, and the melodrama of early adolescence.
The only real fallout has been some slightly awkward (for the adult party) conversations between small children and unsuspecting adults. Oh, and the time I asked my older sibling's friend if he had started nocturnal emissions yet. In front of a table-ful of other early teens. (It's not appropriate dinner-table conversation?)
So I'll say that I think this is a fabulous idea...but you might want to add that people have various levels of comfort with talking about bodies in public.
