The tutorials are part of the QuickBooks Priority Circle package for having an Advanced subscription, dmckay.
Lower plans does not have access to this add-on packages. This means you can no longer access them after changing subscriptions.
Although, you can still register to tutorial and training sessions outside of the Priority Circle. Here's the link: https://quickbooks.intuit.com/accountants/training-certification/accountant-university/.
The Community is always here if you need anything else.
