There are already microcontrollers that have both arm + riscv support. This isn't something insane.

Those takes are wrong with or without this particular processor.

More like mid-2000s, even with the least charitable interpretation.

There was a time when IBM dominated console CPUs for a massively successful generation (PS3, Xbox 360, Nintendo Wii).

well that's nonsense. IBM does incredibly cool stuff.

https://research.ibm.com/blog

Transmeta did code translation with a software JIT. The hardware side had specific support for x86 semantics, similar to how Apple's M-series has supporting hardware for Rosetta's AOT translation, but neither executes x86 machine code directly.

They were pretty clear at Hot Chips that it's native

If by that you are asking whether it has a dynamic ISA controllable at runtime, it appears not. This looks to be a Z processor with arm instructions implemented.