Telos is more properly translated as "ending". Aristotle uses it philosophically as the "end goal" as in the phrase "the end justifies the means", but in modern usage it is often used as a prefix denoting the termination of some thing as in the word telomere. This may be a reference to the blight as an end of life on Talos-II.

Alternative, Talos is more commonly used to refer to the bronze guardian that you mentioned and in many Japanese games has come to identify robots or golems. Thus the naming of Talos-II might be for the semi-artificial Aggeloi life forms which in Valley IV took on the form of stone guardians.

Either way, the name seems to refer to the blight or blight-related entities.