I'm not sure if there is (yet) such a word; but it's definitely related to the retronym, wherein a retronym is usually defined as a new name for an object or concept to differentiate the original form or version of it from a more recent form or version; e.g., analog watch, landline, and snail mail. in other words, when the old style of blueprints start to be referred to mostly as cyanotypes, the latter term would be a retronym.

(retronym, as a concept, was first introduced in these fora nearly ten years ago (YCLIU). it was actually coined by Frank Mankiewicz in 1980 and popularized by William Safire in The New York Times in the 90s. here is a more recent Safire essay.)