This has been an ongoing problem since the C6. It seems to have stopped with the 2018 C7's and does not affect all cars.
GM Sends Letters to Selected Corvette Owners of Potential C7 Corvette Fuel Tank Leak - Corvette: Sales, News & Lifestyle
General Motors began sending letters to owners of C7 Corvettes to notify them of a potential issue with their Corvette's fuel tanks. Based on those chiming in on the forums, the notice covers Corvettes built from 2014-2017 and includes all models from Stingray to Z06.