IME the only major app limitations are games. All the browsers now have a native ARM version. It's possible to get ARM Emacs, R, Visual Studio etc. Most other stuff works fine over compatibility. I have run into one program that would not install because it hard-codes a check for x64. It wasn't anything major and I cant even recall what it was though.
I have heard about issues with printer drivers but I don't have a printer or any other devices that don't just use some generic driver.
With this update, Microsoft’s emulator will open up support for 64-bit x86 software to use processor extensions like AVX, AVX2, BMI, FMA, and F16C. However, it says 32-bit software still won’t be able to detect the new emulator support, so some programs still might have trouble.
Supporting newer-than-MMX-SIMD CPU instructions may help some games run on ARM now.
To be honest I'd love to try it out with Debian once all the upstream support is merged.