I have not frozen it, so can’t say for sure. However, if I was to freeze it myself at home, I would cook and pull the carnitas as in the recipe, cool and transfer to freezer-safe bags and squeeze out all the air, before freezing. Defrost thoroughly in the fridge overnight (24 hours) and then heat through. Any excess sauce, freeze separately so it can be poured over the carnitas. ALWAYS makes sure frozen food is heated thoroughly before serving.
Maybe check your country’s advice on freezing pork for timelines?
USA: https://ask.usda.gov/s/article/How-long-can-you-freeze-pork
UK: https://www.lovepork.co.uk/how-to-guides/how-to-store-pork/