Makes lots of sense, but it isn’t happening for Macs in my observation. Example, Pages from the Mac App Store:
tom@tom11 MacOS % pwd
/Applications/Pages.app/Contents/MacOS
tom@tom11 MacOS % file Pages
Pages: Mach-O universal binary with 2 architectures: [x86_64:Mach-O 64-bit executable x86_64] [arm64]
Pages (for architecture x86_64): Mach-O 64-bit executable x86_64
Pages (for architecture arm64): Mach-O 64-bit executable arm64
tom@tom11 MacOS % otool -fv Pages
Fat headers
fat_magic FAT_MAGIC
nfat_arch 2
architecture x86_64
cputype CPU_TYPE_X86_64
cpusubtype CPU_SUBTYPE_X86_64_ALL
capabilities 0x0
offset 16384
size 24759680
align 2^14 (16384)
architecture arm64
cputype CPU_TYPE_ARM64
cpusubtype CPU_SUBTYPE_ARM64_ALL
capabilities 0x0
offset 24788992
size 23739840
align 2^14 (16384)
tom@tom11 MacOS %
.