Microsoft released the Surface Go nearly three months ago, on August 2. Since then, the device has only received two firmware updates, one at launch and the other a couple of days ago. Oddly, throughout this time, the firm hadn't published a drivers and firmware bundle for its new device.
That changes now, as the package is available to download. There's only one file (SurfaceGo_Win10_17134_1802010_6.msi), and it's for the Windows 10 April 2018 Update, or version 1803. The file size comes in at 307.8MB, and the page lists the publishing date as October 9, so it probably doesn't even include the firmware update that was made available earlier this week.
Interestingly, there are still no drivers and firmware bundles available for Microsoft's newest devices, the Surface Pro 6 and Surface Laptop 2, despite those devices receiving firmware updates. Presumably, those files will show up sooner rather than later.