That's a good rule of thumb, but by that measure the E71 should be perfect and the E75 should juuuust be turning into a stable, bug free phone. Although true when it comes to Nokia phones, it's sort of BS. Customers aren't beta testers.
Particularly when it comes to E series devices for business users, that strategy is going to hurt Nokia. Tech geeks and phone aficionados may be willing to be patient with a phone until the problems are worked out, but a business dealing with phone bug issues and crashes will be less than forgiving.
These people need to get work done and they need a business oriented phone to pretty much run great out of the box. Otherwise, they'll drop your device like a hot potato and never look back. It explains all those bad Amazon reviews from former Blackberry and E71 owners.