Of course AmigaOS needs to move to ARM* ASAP - cheap hardware, soon over 2GHz, great support, etc. If Hyperion set themselves a target of ARMv8** in a couple of years then they can use the opportunity to bring AmigaOS to 64-bit and add in the missing features (memory protection, etc) at the same time. A clean break for the future.
Without being an Amiga expert, a port to ARMv8 without extensive rewritting might be impossible if AmigaOS is written in assembly.
