No, blending hot liquids in a NutriBullet blender is a bad idea, and can be very dangerous.
The manufacturer has strongly advised against using their blenders for making hot sauces or other liquids, and this came following an incident in which a man sued the company as his model exploded while making hot sauce.
It’s best to stick to a countertop blender for hot liquids, so play it safe and make your Bulletproof Coffee in a model which is designed to withstand heat.