The 9800-40 is an older model for the previous generation of 9800s. 9800-40s are monitorable:
https://documentation.meraki.com/Cloud_Monitoring_for_Catalyst/Getting_Started/Cloud_Monitoring_for_...
The CW9800M is supposed to be monitorable per the Cisco Data Sheet: https://www.cisco.com/c/en/us/products/collateral/networking/wireless/wireless-lan-controllers/catal...
But as best I'm aware that feature is not live yet. You may be able to get info from your account team on an ETA.
If you are looking at purchasing, I would definitely get the CW model and then just waiting to onboard to the dashboard once that's available. The 9800-40 has an announced End of Sale date and the CWs are the recommended migration path.
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