but Obama didn't authorize the plan because a few of his admin people against the plan that requires to arm Kurds, other admin officials support the plan to arm Kurds. After last NSC meeting on mid Jan 2017, Susan Rice called Flynn for his opinion on the plan to arm Kurds who will be main force to attack ISIS capital Raqqa. Flynn told her "please don't approve it". Flynn strongly against arming Kurds as a few of Obama admin officials did too.
Because Obama didn't authorize the plan, officially Obama has no plan. Trump admin think Obama administration had delayed authorizing the plan because they knew it was inadequate and did not want to be held responsible. To arm Kurds or not to arm Kurds, it' a tough decision. Obama admin, recommended to arm Kurds though, didn't make the call. Where to train Kurds, how to arm Kurds, how many U.S. military forces needed, the Plan has no details. Also, there is no plan B prepared.