“Best by” is different to “use by” and isn’t saying it’s unsafe to consume due to spoilage. For an unopened and powdered product like bone broth, there isn’t even enough water within the product for it to go off.
For those kind of things, best by usually refers to either taste (because oils go rancid) or nutritional content, because nutrients degrade over time (most likely answer in this case).
It’ll be safe to eat, just probably nutrient devoid.