It might be more likely that WASM is used for its sandboxing qualities while providing "near-native" performance for all types of extensions (not just the aircraft computers), because new aircraft modules and extensions are often provided by third-party companies or the modding community. Traditionally, scripting languages have been used to integrate "untrusted code" (e.g. DCS World, another popular flight sim, uses Lua for its aircraft modules and also exposes a lot of other functionality through Lua scripts so that they are moddable).
WASMtime means you can run webassembly data on the fly from memory.
Innative compiles everything into a proper linkable C object, so you can link it as if it was natively compiled. It embeds LLVM so it should get decent performance out of everything.
