My organization is not currently experiencing any problems, but most of our Macs are only running macOS 14.x Sonoma. Except for the brand new just released models, none are using macOS 15.x Sequoia (at least not in the general group).
Traditionally WiFi related issues are due to issues with the Access Points. First try power cycling the Access Points as that can fix things many times. If that fails, then you will need to perform some type of monitoring on those Access Points and possibly even the Macs themselves in order to figure out what is going wrong. More than likely the Access Points should provide more relevant information.
Also, what recently changed with those Macs, with the Access Points, with the network & switches? Any one or even a combination could be the reason for the issue. Are any of the Macs working? If so what is different between those that work & those that do not work.
Have any security certificates expired and need to be approved on the Mac again? Try turning off WiFi on the Mac, then try turning it back on to see if you get any prompts when attempting to reconnect again.