This seems like a contentious issue so I can only say what I have heard. The answer from those that have built will be NO. Those that haven't will say it must! All logs that are green will shrink in diameter towards their own center. So, if you have built a butt and pass wall and pinned it using rebar those logs shrink "within" the rebar. This will not cause any settling of the walls. For me this seems to make sense.