Of course not. Why would they want to tell you about losing trades up front? Brokers make money from you trading, not being cautious - and they have "trading schools" to provide them with an endless stream of suckers, so the quicker you lose your money, the happier you'll make them. Come on, dude, have some balls - YOLO that shit, that's what margin is for! Those 5-delta calls aren't going to buy themselves, you know.
It is trivial to calculate using Excel, a report from your broker, and some elbow grease. Your Kelly Number is based on the performance of your personal trade history and as a result it would not make sense for a generic trading platform to be able to calculate this information.