Leaked 3DMark benchmark data (spotted by WindowsLatest) shows a new Microsoft device using an AMD Ryzen 7 4800U processor. While there’s no specific mention of a Surface Laptop 4, it’s fairly safe to assume this is the laptop in question since the Surface Laptop 3 adopted AMD chips last year. This processor is also intended for ultra-portable devices, and the Surface Laptop range fits that description perfectly.
Renowned leaker @_rogame has also found a benchmark leak alluding to a Microsoft device featuring a 2.7GHz Intel Tiger Lake-U processor. This means that it’s very likely that we will see the Surface Laptop 4 available in both AMD and Intel flavours, although we don’t know whether the Ryzen processor will be exclusive to the 15-inch model like with the Surface Laptop 3.