Earlier quoted context omitted.
If you opt out you lose access to basically every feature you're paying for. No conversation history, no access to plugins, etc.
Are you sure about that? Parent was not referring to the "APP -> Data controls -> Chat History & Training" Radio Button which would delete your history older than 30 days, but rather to a specific form you can use to opt out. Coincidentally I just used this form yesterday and got the confirmation about opting out.
So if people are going through the steps now they might indeed think that they no longer have access to advanced features.