It is an open secret that certain countries lobbied for the WHO to include gaming disorder in the ICD-11. It was a political decision, not an evidence-based decision. Of course they're going to find it "challenging, if not impossible" to document their rationale.
. IIRC, he mentioned having had correspondence with WHO at CHI Play a few years back. Supposedly they said the quiet part out loud while talking to him. Hopefully there's paper trail.