[thegreatbeanz]

The bitcode used for watchOS is not stable. There’s a special ABI for watchOS that uses 32-bit pointers on 64-bit hardware to make the IR representation stable, but the bitcode itself is still version locked to the compiler.

Apple’s bitcode submission tooling relies on bitcode being forward upgradable, and properties of the ABI to allow it to be retargeted to different SoCs.