Don't think so, since drops have to be initiated in your territory, and barbs have no territory. But, as they say, absence of evidence is not evidence of absence. There are other examples of situations where barbs get special rules (e.g., barbs spawning when pillaging trade routes, barbs not suffering resource penalties for units that normally need horses, or iron, etc.), so barbs might be able to paradrop from anywhere -- just haven't seen them do it.