So, what is it with media personalities (TV/radio) nowadays? Ditto with folks (often journalists!) being interviewed by same! It seems like they INVARIABLY start their replies to any inquiries with "so, ..."
So, this seems pretty unprofessional; as if they'd never had any formal writing/speaking training. You hear it LESS often when Joe-on-the-street is interviewed... more when someone who SHOULD know how to construct a better reply is questioned.
So, is that, perhaps, how they are being taught, nowadays? Or, like all pilots trying to emulate Yeager's casual form of "incredible understatement", just a bad habit they've picked up from colleague?
So, listen more carefully and see how often you hear it "on the street" vs. "from professional journalists"...