An article about some species of octopuses that have a relatively high IQ, but since the parents die before their offspring comes to life, every generation have to relearn everything from scratch. IIRC, the lack of inter-generational communication deprived this species from developing to the level its IQ permits. I wish I can find that piece again!
I had highly educated parents (university professors) and what I learned from them was a tiny fraction of the total amount of things that I've learned so far (from written material, other people, and life experience).
I think there's merit to what you said, but I don't think the crucial bit is the parents specifically. I think the crucial bit is that without language you can't easily communicate to others what you've learned, at least not complex things. This aspect doesn't depends on life expectancy as much. Instead it depends on two things: how much knowledge there is in society (of octopuses) and how doable it is to communicate that knowledge.