Your understanding is not correct.  See §1297 for definition of PFIC, which refers to the foreign corporation and the kind of income/asset it has, not whether it invests in US or foreign securities.

Investing in ETF's or other mutual funds whether through an investment account or foreign pension plan can trigger PFIC tax and/or reporting requirements but there are exceptions.  Part of this has to do with the type of pension and trust it is as well as whether treaty protection is available.

It is also not correct that none of that is reportable for FBAR and FATCA.

Penalties for getting these wrong are substantial.  You need to tread carefully here.