I'd love to know the answer to this too. When they ran it, the installers outright told us they were running fiber for Sonic, and that they thought we'd be able to hook up shortly. We were so excited that we let them continue to block our driveway and parked down the street running back and forth in the rain.
Sonic's answer in the past has been that it was run for a business. Well, there are no big businesses along my street, and the street does not connect any businesses.
Now both my kids are going to be doing college online next semester. Fiber should would lessen that blow.
Thanks for any answers, Sonic.