For those affected (including me), I've documented the following AAdvantage # touchpoints or issues that will need to be addressed - hopefully AA will address some of this proactively, but if not:

- Existing itineraries (including partners like BA/CX); think these need to be manually updated by AA reservations, possibly doable via Finnair site?
- OTAs (Expedia/Orbitz et al) and/or corporate booking tools
- Business Extra, if you have an account
- Citi credit cards
- Hotel programs (HHonors)
- Car rental programs
- Missing 500-mile upgrades (seems like all of us)
- Missing companion/credit card information
- Replacement AAdvantage cards, Citi credit cards
- Admiral's Club membership
- If you've merged/combined with your US account, no idea if that process will be broken; doesn't seem it can be undone on the site (once you're linked it kicks back an error message)