I explained it above.
Lots of guys decommit at a coaching change. Lots of guys recommit to the new coach.
Iuli is from Tacoma, Washington. He had a multi-year recruitment to Oregon under Mario, which is why he paid respect to Mario by visiting Miami.
We've had this discussion before, on west-coast Polynesian players and how hard it is to get them to come to the east coast. He was never coming to Miami. If you want to give Lanning ALL THE CREDIT for the entire 6 weeks of recruiting and relationship-building he did, and ignore geography and everything else, that's up to you.
I guess you were also surprised by Haulcy spurning his "former coach" and choosing to stay close to Texas and play for an SEC team. Shocker.
As long as Oregon hires a competent coach to replace Mario (which Lanning absolutely is), Iuli is re-committing to Oregon. No question.