Well, if you want to remove the AP sending informations to SIEM, then just remove the syslog configuration from the Wireless Controller.
There is a well known issue for the AOS you have and the AP Model which you have:

Or, if you want selective logs to be transmitted then you need to adjust the syslog export filters. However, your Aruba OS is very old you should maybe consider upgrading it.
------------------------------
Shpat | ACEP | ACMP | ACCP | ACDP
Just an Aruba enthusiast and contributor by cases
If you find my comment helpful, KUDOS are appreciated.
------------------------------
Original Message:
Sent: Apr 22, 2025 10:38 AM
From: rnair
Subject: How to disable syslogs of individual APs in Aruba7210 WLC with version 6.5.4.12
Yes Shpat, WLC is configured is send logs to SIEM, but out of 400 only 11 APs are sending logs are utilizing the licenses of SIEM.
Original Message:
Sent: 4/21/2025 5:49:00 AM
From: shpat
Subject: RE: How to disable syslogs of individual APs in Aruba7210 WLC with version 6.5.4.12
I am not sure that the AP is sending syslogs to the SIEM. It would rather be the Aruba Wireless controller.
Have you configured the Aruba Wireless Controller to send Syslog messages to SIEM?
------------------------------
Shpat | ACEP | ACMP | ACCP | ACDP
Just an Aruba enthusiast and contributor by cases
If you find my comment helpful, KUDOS are appreciated.
Original Message:
Sent: Apr 18, 2025 09:22 PM
From: rnair
Subject: How to disable syslogs of individual APs in Aruba7210 WLC with version 6.5.4.12
HI All,
We are seeing that soe of our APs are sending syslogs message to SIEM collector and consuming the licenses. I would like to know if we have any option to disable sending AP specific syslog messages to SIEM.
We have AP 315 and Aruba7210 WLC with version 6.5.4.12