A new update for preview members is available and improves the party chat functions. There is a new update available for preview members, as of 6:00pm PST January 28th, per the Xbox One Preview Program App/Hub/Dashboard.
The update brings a few tweaks to the Xbox One Party Chat:
1)Chat connection status icons:
New icons have been added to let you know the current status of a chat connections in your Party.
-Clock icon: Means the connections is being made.
-Squawker Ring icon: Indicates the connection was successful.
-X icon: Means that networking limitations, such as, strict NAT or moderate NAT are preventing the chat connection from completing.
2) Improved connectivity between multiple users with Strict or Moderate NAT.
3) Fixes from Update: An issue where unsnapping the Party App quickly after joining a Party caused the chat to become inoperable.