You can opt out from your Articulate account, however the buttons remain on the interface and it displays popups about AI Assistant if you click on them, including a button that emails your account owner to request it. To have it completely disabled, the account owner needs to email the request: Articulate 360: Disabling Articulate AI Services - Articulate Support
I'm not sure of the turn around on having it completely disabled. We requested to completely disable it on Friday because we already used the Articulate account to opt out and received a response to use the Articulate account to opt out. I'm hoping they resolve it soon to help resolve the confusion for our team.