Can any bones (but specifically Beef Shortribs) be used to make bone broth AFTER they've done a stint in the crockpot?
Yes and no... You can certainly toss them in a pot and let it simmer for a few hours, you'll extract some flavor and there's no danger. But broth usually uses bones that have only been roasted, not cooked low and slow in liquid as I'm guessing you did in the crock pot. Depending on how long you cooked the previous dish, some or most of the flavor and even the gelatin could already have been extracted. Speaking of that previous dish, any spices used will most likely have imparted some flavor to the bones while cooking, which will then end up in the broth.
Personally, a lightly flavored Caribbean broth doesn't sound particularly appealing to me; I would just toss the bones. But there shouldn't be any danger to trying it if it does appeal to you.