I don't doubt that there are people in this world that are stupid enough to freeze off their healthy normals. I have a hard time believing that the practice is widespread, particularly with large breeders. A large scale breeder produces snakes to make money. Those normals are worth money. They are still a source of income, particularly if you get a lot of them. Say they get 20 normals......who do you know that would throw away $200 bucks? A large scale breeder might produce hundreds, and that is a lot of profit to be tossing in a freezer and throwing away.
I have heard of possible hets sold as normals from a guy I know who buys them for his pet shop. If it's not a new morph and a visual male breeder is relatively inexpensive, I can see it happening. After all, how much is someone going to pay for a 50% het albino male? 100% het albino and pied males are going for very little and don't seem to be easy to move. But even if it's being sold as a normal that is still money in the breeder's pocket and the breeders who I know don't despise money.