You do know that Popes sometimes speak on behalf of the Church and sometimes speak on behalf of themselves, don't you?
The "1980 encyclical" you refer to was not an encyclical; it was a declaration from the prefect of the Congregation for Doctrine of the Faith, and was written by Franjo Cardinal Seper, the prefect of the CDF at the time.
It did not address the issue of nutrition and hydration directly, but reiterated that normal care must always be given:
When inevitable death is imminent in spite of the means used, it is permitted in conscience to take the decision to refuse forms of treatment that would only secure a precarious and burdensome prolongation of life, so long as the normal care due to the sick person in similar cases is not interrupted.
If you're going to lecture people on what the Church teaches, get your facts straight.