There's no mention yet of Junior Gorg, though if the series sells well hopefully Funko will add him to the collection too! He would be neat to see as a 6 inch figure. Here is the official announcement for the series: https://funko.com/blogs/news/coming-soon-fraggle-rock-pop
Update: Uncle Matt was announced on Nov 1st, 2017 as a Funko Speciality Series addition:
Here's more info about other Muppet and Jim Henson related Funko Pop figures:
Flocked Red Fraggle is exclusive to Books A Million
Sprocket is exclusive to Toys R Us
Uncle Traveling Matt will be released as part of the Funko Specialty Series!