They stopped providing completion estimates after the Berkeley fiber delays. They also don't provide activation maps, most likely due to competitors sneaking in where they plan to build. Too lazy to lookup all the threads where they talked about these various topics. Here's a recent one tho.viewtopic.php?f=10&t=16047
Usually they build fiber in an "area", which pertains to a neighborhood or two. So the 13% is in fact your area as stated in the email. Sounds like they have quite a bit to go until completion.
If you are worried about being stuck in a contract with a competitor when fiber becomes available, Sonic does offer contract buyouts.
Don't worry, it's coming - just gotta be patient a bit longer. Just be glad it's Sonic fiber and not ATT fiber or Comcast's wanna-be fiber 1GbpsDL/25MbpsUL. They are many people desperate to be on a preorder. It's worth the wait.