A sealed pot evaporates nothing, and carnitas has to end dry
Browning cannot start while there is liquid in the pan, because water holds the pan at its boiling point and colour needs a surface well above it. A slow cooker is sealed and runs below boiling, so the liquid you put in at 8am is still there at 6pm — plus whatever the pork rendered into it.
Every other braise in this family ends wet and is perfectly happy about it. This one does not. So the drain is not an optional tidy-up at the end, it is the step that makes the second half of the recipe possible, and it is the step slow-cooker recipes are most likely to gloss over.
Any active post-braise crisping step (pan-searing, air-frying, oven-baking at 400-450F, or broiling) reliably produces good browning (6-8/10) on shredded carnitas, regardless of which specific method is used.
What to do: tip the pot into a colander set over a bowl, spread the pork thin on a tray, and give it a broiler or a 400–450 °F oven for a few minutes. Keep the liquid: skim the fat off the top for the crisping, and reduce the rest into something to spoon over.