Thanks everyone for the clarification! Based on the general consensus I thought I'd successfully exported a universal binary (I had 2 versions of Xcode on my Big Sur computer, 10.3 and 13.2.1) and didn't have a way to check until I recently borrowed a fresh, Rosetta-less M1 laptop and it didn't work. In lieu of holding the laptop hostage, I looked into how to check on any Mac via Terminal:
Export plugin
Right click > "Show package contents" > Contents > MacOS > [plugin executable file]
Type "lipo -archs " into Terminal and drag the executable in.
Terminal returns "x86_64 arm64" if it's a universal binary and "x86_64" if it's Intel only.
Mine were Intel only at first because HISE was using the older version of Xcode to export (I'm guessing because that's what I used to compile HISE itself), so I just had to open the autogenerated Xcode project in the newer Xcode version and export from there. Everything was already set up correctly in the file, so I assume you would not have these issues if your whole setup was not based on an older version of Xcode.