Happy to add some references and beef up the text when I get chance. But here's one quote from Ratzinger which comes directly before the quotre about it being a" fundamental threat to the church."

1. Liberation theology is a phenomenon with an extraordinary number of layers. There is a whole spectrum from radically marxist positions, on the one hand, to the efforts which are being made within the framework of a correct and ecclesial theology, on the other hand, a theology which stresses the responsibility which Christians necessarily hear for the poor and oppressed, such as we see in the documents of the Latin American Bishops' Conference (CELAM) from Medellin to Puebla. In what follows, the concept of liberation theology will be understood in a narrower sense: it will refer only to those theologies which, in one way or another, have embraced the marxist fundamental option. Here too there are many individual differences, which cannot be dealt with in a general discussion of this kind. All I can do is attempt to illuminate certain trends which, notwithstanding the different nuances they exhibit, are widespread and exert a certain influence even where liberation theology in this more restricted sense does not exist.

As can be seen he is being quite clear in that only one strand of liberation theology is being condemned.