I am going to go out on a very short limb and predict that Apple does no such thing in the foreseeable future, say 3 or 4 years. In the past, Apple has only transitioned to a new architecture once it was so powerful that it could easily emulate older hardware. Apple doesn't care about backwards compatibility as much as Microsoft on desktops but even they cannot release a new desktop/laptop that doesn't run existing software.
Although ARM processors are fast in certain benchmarks, they cannot compete with x86 for performance and certainly cannot emulate the instruction set at a speed users would find acceptable.
ARM makes great sense for low power devices and _maybe_ servers. Apple already makes tons of the former and seems uninterested in the later.
It should be about 4 years from now that the x86-64 patents have expired, so I wonder (not an expert on anything) if we might see Macs with dual-architecture features after that, whether full support for two instruction sets or just some mixture of software emulation and hardware acceleration for x86.
My iPad Pro is as fast on single-thread as all my Intel desktop machines, and 2/3 on multicore. In a non-thermally throttled enclosure, I would expect it to outperform.
3. rosetta only emulated the actual app binary; eventually it called in to native libs, so performance for the most part held up really well iirc (for apps, not sure about games)
That article is overly optimistic and only works for the very specific, tailored example application. However, Bitcode is essentially repackaged LLVM IR so it's not hard to see it coming to macOS.
Although ARM processors are fast in certain benchmarks, they cannot compete with x86 for performance and certainly cannot emulate the instruction set at a speed users would find acceptable.
ARM makes great sense for low power devices and _maybe_ servers. Apple already makes tons of the former and seems uninterested in the later.