There seems to be tremendous confusion regarding the term, "infallibility." In my opinion, little (if anything) is served by saying that a particular document is NOT infallible. Oftentimes, far, far more harm than good can be done by such statements. To many, to say that something is NOT infallible appears akin to saying that it is NOT authoritative or NOT applicable. In addition to being authoritative and applicable, I believe that much of Dignitas Personae certainly reiterates positions, which have already been infallibly proposed.
In "Contraception & the Infallibility of the Ordinary Magisterium", John Ford, SJ & Germain Grisez discussed how Humanae Vitae was dismissively said to be NOT infallible - simply ignoring such issues as how Humane Vitae reiterated Casti Connubii and other Church teachings:
In "Contraception & the Infallibility of the Ordinary Magisterium", John Ford, SJ & Germain Grisez discussed how Humanae Vitae was dismissively said to be NOT infallible - simply ignoring such issues as how Humane Vitae reiterated Casti Connubii and other Church teachings:
(All of the below images are links....) 
Some suggest that Dignitas Personae does NOT speak clearly (or at least NOT definitively) on the matter of so-called "snowflake adoption", ironically citing the writings of Germain Grisez, William May, and others...
It should NOT be overlooked that the above writings came before these statements in Dignitas Personae:
A more recent article by William May seems more pertinent:
What Dignitas Personae actually says with regard to embryo adoption seems like a diplomatic but clear "No," to me:
