I don't think it is type related in itself, i have noticed plenty NT's zone out ...just in different ways and for different reasons.
For myself if i zone out during a conversation it can be due to many things... most likely i have heard the info befor and am stepping ahead to guess what comes next or how to change the direction. Also i may just have a lot on my mind and be focussing on more than one thing and it so happens i lost the trail of the conversation whilst investigating something else mentally. Also possible is that i'm just not that interested in the subject matter, though that is rare as most things do interest me. Sometimes though if a topic becomes too technical and specific in an area that i am unfamiliar with i may wonder off into dreamland unintentionally. Oh and another thing is when people just waffle on and on and go round in circles without progressing... and have a monotonus tone... gah zzzzzzz