This isn't that surprising, Google has said that it will focus on making Hangouts more of a business app and after December 1st, users will be able to download it from the Play Store.

Meanwhile cross-platform Duo is geared more towards the masses with a simpler interface and "fun" features like Knock Knock which shares a video of a person before a call is answered.

But don't be surprised if come December you see both apps on your new Android phone. Just because Hangouts is no longer a mandatory part of the default OS bundle doesn't mean phone makers will pull it right away.