@DoBongSoon Thanks for posting in our Q&A.
For this issue, when a profile is removed or no longer assigned to a device, it depends on the CSPs and each CSP can handle the profile removal differently. We can refer to the following article:
https://learn.microsoft.com/en-us/mem/intune/configuration/device-profile-assign
At the same time, I find that most CSP settings support "Add, Get, Delete, and Replace" operation.
https://learn.microsoft.com/en-us/windows/client-management/mdm/wifi-csp
And When we remove a device from a group that's assigned the profile, Wi-Fi profile is removed from all supported devices.
https://learn.microsoft.com/en-us/mem/intune/configuration/device-profile-troubleshoot#what-happens-when-a-profile-is-deleted-or-no-longer-applicable
Given this situation, I think the new one is override the old one. Just to be on the safe side, it is suggested to create an online support ticket to find if there is any background information can confirm the new profile is used now.
https://learn.microsoft.com/en-us/mem/intune/fundamentals/get-support
Hope the above information will help.
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