Could we also expect that facebook may have a feature where gambling (that uses crypto/ facebook coin) is allowed?
As far as I know, Facebook is a U.S. corporation. It means that they (Facebook) need to acquire gambling licenses to operate (in the U.S.). I think that gambling is not their business. Moreover, many countries ban gambling and would hurt their core business if they want to operate an online casino.
Furthermore, 3rd party casinos would think twice to add the Facebook coin, because of lack privacy.
So my answer is no.
Facebook is a USA corporation but Facebook users are not only based in the USA. Well, its possible to go into gambling if they decide to, as they might not necessarily need any form of license from any government, its their decision and any country that is not pleased with it might only find a way of controlling it citizens from abstaining or even ban citizens from using the app after all China has banned its citizen for a longtime from using Whatsapp chat and this has not stopped the growth of the application in any way.. if 98 percent of their users are clamoring for coin gambling, i think they would be left with no choice than to approve