While updating 4.15.0->4.15.18, a msg presented as if were upgrading to 4.16

[kni@ocp-edge64 ~]$ oc version
Client Version: 4.15.0
Kustomize Version: v5.0.4-0.20230601165947-6ce0bf390ce3
Server Version: 4.15.18
Kubernetes Version: v1.28.10+a2c84a5

TBD

1.Deploy a hub cluster with 3 masters and on it a hosted cluster with 6 worker nodes, ocp4.15.0, and ACM2.9 I used those jobs for deployment: 
(some envir noise, so it ran in few jobs):
a. https://auto-jenkins-csb-kniqe.apps.ocp-c1.prod.psi.redhat.com/job/CI/job/job-runner/3059/
b. https://auto-jenkins-csb-kniqe.apps.ocp-c1.prod.psi.redhat.com/job/CI/job/job-runner/3064/
c. https://auto-jenkins-csb-kniqe.apps.ocp-c1.prod.psi.redhat.com/job/CI/job/job-runner/3067/

  2.update test for ocp 4.15.0->4.14.18, failed on timeout :
https://auto-jenkins-csb-kniqe.apps.ocp-c1.prod.psi.redhat.com/job/Private_Folders/job/gamado/job/WIP-ocp-edge-auto-tests/55/testReport/deployment.upgrade/test_upgrade/test_hub_cluster_upgrade_quay_io_openshift_release_dev_ocp_release_4_15_18_x86_64_/

 3.

[kni@ocp-edge64 ~]$oc adm upgrade

 
info: An upgrade is in progress. Working towards 4.15.18: 131 of 873 done (15% complete), waiting on kube-controller-manager, kube-schedulerUpgradeable=False  Reason: MultipleReasons
  Message: Cluster should not be upgraded between minor versions for multiple reasons: AdminAckRequired,PoolUpdating
  * Kubernetes 1.29 and therefore OpenShift 4.16 remove several APIs which require admin consideration. Please see the knowledge article https://access.redhat.com/articles/7031404 for details and instructions.
  * Cluster operator machine-config should not be upgraded between minor versions: One or more machine config pools are updating, please see `oc get mcp` for further detailsUpstream is unset, so the cluster will use an appropriate default.
Channel: stable-4.14
warning: Cannot display available updates:
  Reason: VersionNotFound
  Message: Unable to retrieve available updates: currently reconciling cluster version 4.15.18 not found in the "stable-4.14" channel[kni@ocp-edge64 ~]$ 

no irrelevant msgs about 4.16 version while updating to 4.15.8