Google Stadia was outlined in further detail in the course of yesterday's (July 18, 2019) AMA on Reddit. Its Director of Product fielded queries concerning the upcoming game-streaming platform's chances of success and longevity; apparently, Mr Doronichev has a great deal of confidence in both respects. This appears to be based mostly on the amount of investment and development Google has already invested in the new system.
Doronichev also confirmed that Stadia will have social features such as a friends list and voice-chat functionality. The platform will also support saves and metadata retention via Google Takeout. Some participants in the AMA wanted to know where they would stand with respect to Stadia Pro's advertised free games should they unsubscribe from this subscription and then resubscribe at a later date. The answer is that they would not gain access to those free titles that they had missed during the period of non-subscription.
On that note, this tier of the product will apparently contain free games, which will drop at a rate of approximately 1 per month. The Google executive also confirmed that Stadia will exhibit its own version of Achievements, but that they will not be ready at its November 2019 launch. Finally, the new platform will help users control the amount of data that this form of streaming is liable to use.