Right now, if an event is connected or a continuously active thread is initiated in the output, they will not be disconnected/cancelled until the studio session is closed.
When wanting to test something involving hooking a while loop to a thread, or connecting an event, the output would probably be the first choice, and as such, it would be nice if clearing the output, either with the “Clear Output” option under the right click menu, or the trash bin button, disconnected all these events, and cancelled all these threads.