After your Printful Pro subscription ends, you won't be able to order products containing premium content or access your Promo Maker images.
Product templates and synced products in your store will still be visible. However, orders with products containing premium cliparts or designs with BRT layers will be imported as Failed. In order to continue submitting orders with these products and/or templates, you'll need to either edit the order, the synced product, or the template to remove the Pro layers, or resubscribe to Printful Pro.