Though not nominated yet, Ruger is undergoing vetting, and has been meeting with officials. The Vice President for Research and policy at the Charles Koch Institute, Ruger has frequently advocated ending the Afghanistan War.
Though the US is heading toward ending that war anyhow, with so many officials taking a wait and see approach, having a proper ambassador who is known to want a pullout would be a clear signal the administration intends to complete the process.
According to Politico:
Ruger, a Naval Reserve officer who served a year in Afghanistan a decade ago, is aligned with the president's thinking about the U.S. footprint in the Middle East and the wars in Afghanistan and Syria, and has been especially vocal about getting out of Afghanistan.