I know you IT folks install OS/applocations like a biological function, buy I really try to avoid installations as much as possible. I figure in time, suffering, and software cost it's worth at least $1000 for me to avoid an installation. If I drop a new Granite Ridges CPU into the AM5 sicket where the 7950x is now, is it correct that the computer won't even boot into Win 10?
I sincerely doubt that will be the problem.
More than likely, the issue you'll run in to is that the driver installation packages for your motherboard will refuse to run as straight up executables. That'll be the AMD Radeon-whatever driver for the CPU's integrated graphics; Ryzen Master, the chipset drivers; and/or the storage drivers. The devices on your motherboard won't have changed, so we know that things like storage and USB will be whatever they were before. We don't have a circumstance where AMD is switching to a P/E-core deal like Intel did.
When AMD launched Ryzen 3000, it didn't provide Windows 7 support and just like Windows 10, there are die-hards who have said they're never going to change. That just meant I had to do some extra work to get a new Windows 7 install up and running. It was not impossible, just obnoxious, specifically because the installer didn't recognize USB devices until the install was finished.
The solution was to open the driver installers using an archive extractor like 7zip, grab the files I needed and change a line in a couple INF files.
You will probably have to flash a firmware update to install the new CPU, but your existing Windows 10 install isn't going to stop working with your current CPU. You will probably have to find workarounds for ( ? ) entries in Device Manager if you switch CPUs. It's not the end of the world.