Google already has Google +, but it's rolling out Spaces. They have GoogleVoice, Chat and Hangouts, but are rolling out Allo and Duo. While it's confusing to the general market, it's really a way to say that they are coming out with something totally new and not just upgrading what they had.
The reason "NEW" is part of "NEWS" so if it was simply said at Google I/O that Google is going to upgrade their existing offerings it would be a yawn instead of a boom. And, judging by all the media attention SPACES, ALLO and DUO are getting, along with other "NEW" announcements, one would have to say the positioning is working.
What Google did was get into the game where Facebook already is with Messenger and WhatsApp and now will have native apps that mirror Facetime and iMessage from Apple. Already Spaces is working on both iOS and Android, while Allo and Duo will be out later this year, likely to coincide with the arrival of the new Android OS and the new Android Nexus devices (smartphones and tablets.)
As for Spaces, the idea seems good as it feels like a "Post It" note service, complete with commentary....but for more personal, small group use vs. Google+ which is more of their Facebook alternative.
So give Google's spin doctors credit. They could have simply said "we're upgrading Hangouts" but instead their leaving Hangouts to be their Conferencing solution to rival Zoom, GoToMeeting and WebEx, while making their two new apps more about personal communications...