2013 MacBookPro with Nvidia GPU and recent macOS
What you've been reading about are the third party nVidia Web Drivers, which nVidia created (primarily) for Mac Pro users installing new graphics cards in their towers. The nVidia Web Drivers do not work in Mojave or newer, leaving users of those GPUs stuck on High Sierra.

Your nVidia GPU is natively supported by Mac OS, and will continue to work in Mojave / Catalina.