Which part of the article covered the 2012 announcement? There was the piece near the top: `earlier this year, we announced that we started using the bsdiff algorithm (by Colin Percival).`
But earlier this year would be 2016, not 2012 so I assumed that this was something else.
And clicking on the link in your quoted text would give you this:
> Google Play has used delta algorithms since 2012, and we recently rolled out an additional delta algorithm, bsdiff