I very strongly recommend it! I don't add a lot of salt to the meat while cooking the meat. So, when the braising liquid is reduced, it concentrates the flavors in the carnitas, including the salt. This reduced braising liquid is added back to the shredded pork carnitas so that it seasons and adds even more flavor to the meat! It also keeps it juicy. If you don't reduce it, the flavors will be too diluted.