Sam Robinson's Quick takes

Yeah I think uptalk originated or at least was popularized in southern California, originally known as the "valley girl" inflection. As with many linguistic trends popularized by young women, the speech pattern a) is commonly derided, partially for gendered reasons and b) has increasing uptake as a linguistic innovation. 

However, as OP noted, there could be social and even professional consequences of speaking in a less prestigious register, so people should take that into account. See eg this Time article:

Have you ever held a conversation with someone and found yourself questioning whether or not he or she was making a statement or asking a question? The person was probably guilty of using up-talk, or speaking with rising inflection, usually tacked on at the end of a sentence. The tone is said to have origins in California Valley girl culture, but D.C.-based vocal coach Susan Miller, says the uncertain, youthful tone is prevalent across both states and genders—despite the assumption that women are the prime culprits of up-talk. “I would say that the majority of employers come to me because people sound young,” says Susan Miller, a D.C.-based vocal coach and speech pathologist whom employers engage to help employees sound more professional. “And it’s the up-talk, the uncertainty, more than fry.”