iDeCo & PFIC exposure for a US taxpayer

Hi all, complicated topic and I have seen a few similar ones in the past, but nothing too recent. For context, I am not a US citizen but will be moving to the US next year and will become a US taxpayer. I am trying to understand my PFIC exposure and reduce (eliminate) before moving. I have already sold everything in my securities account, but I am now looking at my pension. My company provides a DC account which I have used for almost 6 years, with various products invested under the hood, all of which I believe would be PFIC exposed.

As I leave, they will rollover my pension to an iDeCo, but as of right now it's not clear if the money in there will be held in cash or invested into some mutual funds, etc. I have been told that I will not be able to make iDeCo contributions, but asset transfer into the iDeCo is okay.

So the question is, if the money in my iDeCo is invested into vehicles which would usually be PFIC-exposed, would the iDeCo wrapper be eligible for the foreign pension exemption? Based on previous conversations in this subreddit from 5 and 2 years ago, I believe the answer is "who knows since the IRS haven't explicitly stated anything"- so I am wondering if either this is an incorrect conclusion of these threads, or better yet, there has been an update from the IRS on this.

Essentially, do I need to ensure everything is held in cash?

Thank you!

by Riverofrhyme