When Modi announced it, he used Black Money under the garb of Black Money. Later on goal keep shifting. From damaging terrorist/Naxal money to digital transactions.
https://www.thehindu.com/opinion/editorial/shifting-goal-pos...
https://indianexpress.com/article/india/demonetisation-rbi-a...
https://economictimes.indiatimes.com/news/politics-and-natio...