docs: update changelog with known limitations

changes/ce/feat-14360.en.md

@@ -6,3 +6,5 @@ Example output:
 emqx_client_disconnected_reason{node="emqx@127.0.0.1",reason="takenover"} 1
 emqx_client_disconnected_reason{node="emqx@127.0.0.1",reason="kicked"} 1
 ```
+
+Currently, this feature is limited to TCP and TLS listeners only.