Bing has quietly dropped the Twitter option from the Bing Webmaster Tools Contacted Pages option. Bing said "by adding the various web presences as "connected pages" in Bing Webmaster Tools, you can get an overview of how many impressions and clicks you are getting not only for your main website, but also for each of these connected pages."
This feature launched in 2009 and is still live today but it currently doe not work with Twitter.
You can access this by logging into Bing Webmaster Tools, clicking on "Configure My Site" and then the "Connected Pages." You can use the Connected Pages tool to connect related web presences, such as your social media pages, app pages, image or video pages to your verified website and see their performance in our search results.
The help documents say Twitter is supported but it is not, go check for yourself, it is missing. This is what the help document shows but if you login, Twitter is not there:
Jacques Bouchard shared this email with me about this on Twitter:
.@Marie_Haynes @rustybrick @dr_pete Tiny news update, but if you're interested, Bing Webmaster Tools no longer allows users to connect Twitter accounts in Configure Site. I got three of these notifications today. pic.twitter.com/dKxjvvZ2x4
— Jacques Bouchard (@jacquesbouchard) April 9, 2020
Forum discussion at Twitter.