I agree with you that CoinMarketCap never advertises gambling. It is usually handled for use in the use of cryptocurrencies Casino sites are different in the crypto market Making money here is much easier. Gains more exposure on social media.
I see some ad banners of some casinos on coinmarketcap.com, Sportsbet.io, Bitcasino.io. They are casinos I saw last few days. Maybe more sites are advertised and displayed on coinmarketcap.com. I don't know there will be changes in advertisement strategies and requirements on coinmarketcap.com because of impacts from Binance.
I still can't believe that binance bought out coinmarketcap, but looking at the website they didn't really bought it to integrate with binance and somehow make it like their website or anything. It looks like they bought it because they think it could be a business all by itself. I wouldn't really spend that much money on a ranking website if I wanted to grow, but it has a ton of users so I guess it makes sense to them financially.
About the ads, they would definitely allow gambling ads, I have seen plenty of gambling ads there, and I think binance doesn't mind as long as its a legal situation, if you are running an illegal casino with no license you wouldn't go too far, but if you are doing something legal and not nsfw, you can advertise anything there, including freebitco.in which would profit anyone highly.