I do not know why the Binance adds a new trading pairs for a ripple, but this will obviously lead to an increase of the price of XRP. I do not believe in the ripple itself but you can buy it just to take some profit
I don't trust USDT and still it has a lot of success. People don't care much what tools they get as long as they can speculate and earn money off that.
Maybe, just maybe Binance has come to some interesting ideas when Tether price had its strange days with 0.95-ish price: with a coin not pegged to US Dollar even larger fluctuations are possible and maybe Binance can benefit.