Update 4:24 PM EDT: Official patch notes are listed below. No mention yet of a free packs event.

Hearthstone Patch 5.2.2 - Free Packs Event?

A new patch has been pushed the the live servers. Within it, an activate flag was updated under an event!

set_rotation_2016_free_packs is no longer set to None but rather "set_rotation_2016_free_packs"

We aren't certain what this means but we'll update if we find out!

Official Patch Notes