fix(Slack Node): Refine label name for reply broadcast setting (#15658)

Co-authored-by: Your Name <you@example.com>

packages/nodes-base/nodes/Slack/V2/MessageDescription.ts

@@ -673,7 +673,7 @@ export const messageFields: INodeProperties[] = [
 									'Message timestamps are included in output data of Slack nodes, abbreviated to ts',
 							},
 							{
-								displayName: 'Reply to Thread',
+								displayName: 'Also Send to Channel',
 								name: 'reply_broadcast',
 								type: 'boolean',
 								default: false,