Freezing coffee beans can be bad if you don't store the coffee beans in an airtight sealed container when you freeze them.
If you do not place the coffee beans in an airtight sealed container when freezing them then overtime the coffee beans can suffer from freezer burn.
That would make the coffee beans not as good to use.
It's best to just refrigerate the coffee beans but also keep them in an airtight sealed container.
Using the coffee beans up before they get too old is also best because they will remain fresher and give you a better tasting cup of coffee.