@Sina thank you so much for the note, you’re absolutely right!
Guys, we’ve double-checked things and found that Bing just displays reviews from another sources, but doesn’t let users leave reviews directly on Bing (like Google does).
Most of the reviews sources from Bing like TripAdvisor, Yelp, Facebook are already available as standalone apps and supported in our All-in-One Reviews app.
Since there is no need in a Bing source for All-in One Reviews, we’ve decided to mark this request as “Released” 