I'm assuming that they dismissed it as a user error at that point.
If they had discovered the mistake, the later firmware would have fully addressed the entropy problem, right? (ha! maybe not, but it does seem more likely)

The thing that my mind keeps tripping on is this: if they did in fact discover it at some point, there would have been no way to alert people without giving hackers the pointer as well. It's crazy, but the only thing to do at that point would be to fix things in the firmware updates for future wallets. For the affected wallets... what, send out messages encouraging people to roll dice and upgrade their seed but somehow do that without alarming anyone or giving it away to hackers. "Hey, now that you have a hardware wallet, why don't you learn to re-do your seed! Let's all do that together! come on, it'll be fun!" Or - "hey, we have a firmware update and it's amazing so please everyone install. Today. And actually it will require new seeds."