Wifi 6e is a perfect example of why soldered Wifi chips are dumb move, planned obsolescence on devices that aren't exactly cheap. Qualcomm just announced Wifi 6e solutions that will become available by the end of the year and will more than double the number of available channels today on Wifi 6. With the economic impact of COVID 19 likely to give companies fiscal headaches and dampen consumer demand, why on earth would you create a device that will be Wifi obsolescent in less than 6 months?
Dell really is trying to pull a fast one on consumers (typical). Yes you can put in an a M.2 A+E to M.2 M adapter in the second M.2 slot and get around this problem. Amazon has the adapters. However it's a really stupid ploy on Dell's part. Other vendors are not soldering their wifi parts. So maybe consider whether Dell is worth your money.