Okay guys, I have some bad news to report.
European gamers will get the patch later this week, but we hit a last-minute snag with the American version. I know you guys are sick of hearing about delays, and I want to be totally transparent about what happened.
As the update adds new content, the save games cannot be be backwards compatible. If you have a 1.02 save and you roll your game back to 1.00, the save game won't work on the older version. It can't: if your save game has v1.02 items, the 1.00 game won't know what they are. So save games not being backwards compatible is expected - and necessary - behaviour.
Unfortunately, we didn't 'future proof' the 1.00 code properly. Instead of it saying 'that save is from a newer version, I can't load that', the game tried to load it and encountered a fatal error. Nintendo of America needed us to implement this differently so that the fatal error was avoided.
Fixing that is tricky, because we can't go back and add code to the 1.00 version to handle this better. That version is out there and on carts. Instead, we had to change how 1.02 deals with save games.
So now, when you update to 1.02 the game changes the save games so that a rolled back 1.0 version no longer recognises them as save games. So if you roll back, you get nothing.
When patching, we already had a warning in place saying that unpatching would render the save games unusable. So all of this behaviour is intended.
There should never be a reason to roll back on the EU version, but if you do the saves will not load.
Rolling back on the US game means you will not see any saves - but they will be there for you again when you re-update.
It's absolutely on us to have handled this better, and we were happy to work with Nintendo to find a solution. I'll keep you posted on the progress through submission and the go-live date once I get it.
Apologies.