All manufacturers are required by the GPL to release the kernel source code whenever there's a change to it, which usually happens when a major update is pushed. The Moto G5S Plus, codenamed 'sanders,' has been waiting for its Oreo update for quite a while now, but with news of a soak test occurring in Brazil and this 8.1 Oreo source code's release, it looks like it may be coming soon.
The Moto G5S Plus is the Moto G5 Plus's successor, offering a dual rear camera setup, metal body, and a 5.5" 1080p display. Depending on configuration, you can get one with up to 4GB of RAM and 64GB of storage. It's not all good news, though; the camera isn't great, and it increased in price compared to its predecessor.
If you're a developer and you'd like to use this source code to start whipping up some custom software for the G5S Plus, hit the GitHub source link below.