Not really. It began to appear in German books in 2005 (https://books.google.com/ngrams/graph?content=Prekariat&year...) and searches took off in the end of 2006 https://www.google.com/trends/explore#q=Prekariat%2C%20preca... The German version of the word is still more common.
It actually really surprised me that the word is so young, as I think the word is pretty much common knowledge in German.