In your previous question you asked about a single 16gb stick, which would bring your total up to 32gb. The 8gb stick pair would run in dual channel and the 16gb stick would run in single channel, in what is called Flex Mode. Once you went over 16gb or 50% Ram usage, the last 16gb would run in single channel.
Regarding the 2x8gb and 2x16gb setup,
As mentioned, If you follow the instructions in the manual then you would be able to run the combo in dual-channel. However since Ryzen processors have a nit-picky memory controller I can't guarantee how stable it would be. The system will most likely downclock the memory to 2133mhz. You would have to tweak and tinker with the memory to get it stable at higher speeds. Remember, the Infinity Fabric speeds are tied to the Memory clock speeds, so you might see diminished performance with a bunch of slow RAM.
Hopefully the Ryzen 3000 series processors have a stronger and more stable memory controller. Also, I would encourage you to read the Memory QVL list for your motherboard and make sure the BIOS is updated.
If you need 32gb of RAM for some reason and you want your 2700x to get the best performance then look at a G.Skill 2x16gb set that uses Samsung-B die memory. Usually this is the 3200mhz cl14 or 3600mhz cl16 stuff.