I just got a notice in my email with a link to their blog post about this change next month. Next month Bing Ads will not show up inside of the web pages , it will still show up on Bing's search results and mobile apps though.
Really! I just signed up to buy ads via Bing. They are still advertising for customers to use content ads. They signed me up for a new content ad campaign (buying ads) a couple of days ago!