Thread bundles exclude ignored users

Per implementation: matrix-org/synapse#12235

proposals/3440-threading-via-relations.md

@@ -51,12 +51,14 @@ would include additional information in the `unsigned` field:
 }
 ```
 
-* `latest_event`: The most recent event which relates to this event, with
-  `rel_type` of `m.thread`.
+* `latest_event`: The most recent event (topologically) which relates to this event, with
+  `rel_type` of `m.thread`. Events sent by [ignored users](https://spec.matrix.org/v1.3/client-server-api/#ignoring-users)
+  are not considered for the latest event.
 
   The latest event should be serialised in the same form as the event itself;
   this includes adding any bundled aggregations for the event (and applying edits).[^1]
-* `count`: An integer counting the number of `m.thread` events
+* `count`: An integer counting the number of `m.thread` events, excluding events sent
+  by [ignored users](https://spec.matrix.org/v1.3/client-server-api/#ignoring-users).
 * `current_user_participated`: A boolean flag, which is set to `true` if the
   current logged in user has participated in the thread. The user has participated if:
   * They created the current event.