This does not sound convincing to me; I can not imagine ANY realistic scenario where artistic activity is only viable because of profits earned more than 20 years later: Not for individual authors/creators and especially not for companies.

I think this point of view only appears reasonable because of how ridiculously extensive copyright terms are right now...

Imagine companies paying bonuses for work that was done >20 years earlier: That sounds to me neither reasonable nor helpful in any way.