I still doubt that even by 2018 or 2019 Charlotte will be able to compete with App.
ODU and UTSA are solid examples of programs that just started up that were able to compete immediately.
South Alabama has only been FBS for a couple years and they're expected to finish top 3 in the SBC this year and will likely be bowl eligible.
App is moving up a level themselves while coming off a bad season. They're not immune to bad years and they'll likely experience a few in a row with the move to FBS.
It doesn't really take much to compete with other programs outside of the power conferences. Few teams in the lower conferences are great year after year after year.