Multilanguage site completely deindexed in Bing

EricStarker
We are in a very problematic situation,
We run a large international website and have been working for several months in the background with a large copywriter staff to get our language sections ready. 
When we launched our site a year ago, it only had two languages and approximately 1200 indexed pages.
When our additional languages were ready, we put these all live during a week as we had to validate many technical details with internal links in the process, so we could not drip-feed them. This resulted in ~10000 new published pages, and Bing found these quickly via the hreflang tags and indexed these as expected. 

Now today, we noticed that our entire site had been removed from the Bing index with the message: 
"Some results have been removed" as the only result.

We have contacted support and received a reply that someone will look at this in 10 days, but this is a huge emergency, and we need to contact a Bing engineer as soon as possible.