I use Citi's virtual account numbers (VAN) for free trials and subscriptions at risk of auto-renewing. It's great. I control the maximum amount that can be charged to the virtual card, and the expiration date.

Rather than this automatic update service, it would be more helpful if the bank could send me an alert when it detects a recurring charge associated with an expiring card number (including VANs). If they want to get fancy, then let me respond to those alerts on their web site to decide if the vendor should get the updated information. There are options here to make things convenient and safe for customers.