Thred are proposing things a little differently to these...

Thred are proposing things a little differently to these companies you have mentioned. It's social media aggregation sure. But it's also workplace collaboration (refer Slack) which includes access to full file sharing capabilities like Word; Excel; PPT etc; the use of NLP (natural language processing) and neural networks harnessing machine learning functionality (learning user preferences for a targeted more satisfying user experience) as a type of smart digital personal assistant as David has stated. You will be able to book meetings and invite people from any SM site to engage in conversation. There is to be an app plus a web version. In order to see comments contained within a Thred you must download the app. However if an invitee does not download Thred they can still participate but will only be able to see comments & content that has been provided by the person who created that Thred in the first instance (not comments or content provided by other invitees). The idea is also to be able to book whatever it is you need (from hotels; flights; concerts; gifts etc) and have location based suggestions made to the user based on how the user uses the app. When you land from a flight for instance it may automatically order you an Uber ride to your hotel and direct you to your pick up point as it knows this is what you prefer so to speak.
It goes well beyond social media aggregation and becomes like a chat bot but imo better.
With Microsoft essentially giving up on the handset wars against Apple & Samsung (a war they know they can't win & would be wasting time, energy and resources to do) they are taking a different tact in their efforts to increase market share in the mobile and messaging space. Look at the recent acquisitions MS have made and this will give you an idea of where their vision for the future lies.
This is a brilliant concept, and whilst I'm sure it shares some similarities to the above mentioned apps it goes well beyond basic SM aggregation.
The bullishness on this for me doesn't just stem from MS integration/involvement but also the people behind it. It's a sharp concept but it will come down to execution and ease of use. With 60m O365 users to be exposed to Thred they would want to make sure they get the basic stuff absolutely nailed down solid as establishing initial critical mass adoption will be the making of this company. With that many people being exposed to Thred it imo will literally be make or break for the company. I have confidence as MS won't want to integrate a sub par confusing app into their o365 suite.