One important point here: In the article the author says that the location of the database is /sdcard/WhatsApp/Databases. That's not entirely correct.
It only gets copied there when you use the build in backup feature (Settings -> Chat Settings). Else, it sits "safely" under /data/data/com.whatsapp/databases like every other Android sqlite database.
But nonetheless, WhatsApp was and is not really known for its safety...