The sixth-generation Camaro does not lack available engine and transmission options in the slightest. You can order a turbo four-cylinder with a manual or automatic transmission, there is a V6 Camaro with a manual or auto option, and of course, there are two V8 options in the SS and the ZL1. The naturally aspirated 6.2 liter V8 in the Camaro SS can be had with an eight-speed automatic and a six-speed manual while the ZL1's supercharged 6.2 liter V8 can be paired with either a 10-speed auto or a six-speed manual. Basically, you can have whatever the hell you want, but Chevy isn't done.
Autoguide.com found a California Air Resources Board document that shows the 2019 Camaro with a seven-speed manual. Now, this isn't confirmed by GM, nor do we know if it would replace the six-speed, but this move would make sense. The Camaro and Corvette already share an engine and, with a refresh on the Camaro coming, an updated transmission would be a welcome addition.