Hub 360 Assignment Behavior
Without previous routing done
When a field unit is establishing a connection on Hub 360, and a Live is started, the expected behavior is to automatically route the incoming Live to the first available output of the server setup in priority. This priority can be changed in Admin Area under Administration > Groups by editing StreamHub Priority

In the CNN account, the current priority is given to server TWD-SH-1001-1003-1005-1007:

Until the unit is not turned off, the route will remain in place. But the routing is not permanent — as soon as field unit is turned off, the route will be released.
There is no way to impact the route from the field unit directly. The change must be done on the Hub 360 side.
With a routing set
GCC can define static routes from Hub 360 Master Control panel.
This can be done with a simple drag & drop action, or by selecting a specific input in the output drop-down list (on the right screen panel).
Once the route is created, it will be persistent. Which means that if the same field unit is disconnected and reconnected later (whatever the time; there is no expiration date for a route), then it will reuse the same route and will be routed to the same destination output.
A route can be changed by dragging & dropping another input thumbnail to output thumbnail, or by cleaning the output and selecting ‘No Source’ from the drop-down list.

Recommendations
GCC should recommend to PJs to not start any Live streams until given the green light (by GCC).