Taliban might not be interested in power outside of Afghan proper, but Taliban is not the only militants around, not anymore.It is just due to CSTO.. If there was to occur spillover but IEA has no interest in that so it is irrelevant all that exercises or talk.. They don't seek any involved in this country
the departure of US troops will severely diminish Kabul control on it's countryside, no matter who is in charge. Making an ideal place for terrorists and armed groups to flourish.