Yeah I'm disappointed too this has diasppeared.
When this was introduced it was great, as it enabled me to get a feel for what was happening in the city.
I suspect this is tied in with SmartPricing, and not wanting peole to know what the actual demand is. I woudn't trust AirBnB to bring it back.
They may as well get rid of a chart of prior bookings because that actually doesnt tell you much you didn't already know.
What is interesting is watching people search for future dates, and see how your listing is performing compared to others.
Also, when trying to plan a holiday or break away for myself its helpful to know what dates my potential guests are searching for so I can book around potential reservations. But, you know that's helpful to hosts, and AirBnB don't have a great reputation for taking our needs into account.