There are fully automated disc burner bots. EPSON models take 100 discs at once and burn up to 30 discs per hour, so 1000 discs is just 10 magazine load/unloads or <1.5 days in machine time.
Load fresh discs from magazine, put onto an internal disc drive, let a connected PC burn it, take out, print on it, and move it to a burned disc holder. All in one box. The networked model does it over LAN like a laser printer.
All the same, they don't need a thousand copies of one GitHub repo. They need a thousand different copies of various unrelated repos. Maybe some disc duplicators can handle that without constant user involvement, but all the ones I've worked with are designed around mass replication of one individual ISO.
Looks like target market of this type of duplicators is hospitals using it for exchanging medical images, where optical discs are still very common as disposable storage medium. I'm sure they don't print hundreds of identical chest X-ray images... This one really isn't bunch of DVD drives wired in parallel to a no-name ASIC, it's one drive stuffed in a microwave enclosure along with a robot to change out discs for it.