What does it matter if you freeze raw mince. You're cooking it after anyways.
I've also never understood when people say you should NEVER consume meat frozen past x months...like, it doesn't matter. It's quality/flavor/appearance that degrades. It doesn't make it lethal or make you sick.
I've done the same with burger patties and meatballs I made. Never had any problems. Hell you can buy uncooked frozen burger patties and meatballs at the store.