Rerum Novarum - issued 1891.  Quadragesimo Anno - issued in 1931.

Yes.  More than 120 years for the first and more than 80 years for the second, which sought to further that discussion on subsidiarity.  

It is about right for the Church to start now making sense of these ideas in how the Church runs itself.  It takes a while.  I suspect another couple of hundred years before some future Council comes up with "as the Church has always taught" and we see substantive change in inclusion of lay people and women.  

Not sure if there will be much of Catholicism left in the developed world by then.  Not sure if the parts of the world in which Catholicism is now growing won't be in the same cycle of decline we are in now.  Educate people and then you have to treat them as educated, aware, thinking, adult.    That is the trick the Church hasn't yet learned.