The website is somewhat non-informative... a more technical post: https://www.nextplatform.com/2021/07/12/gutting-decades-of-a... (especially interesting is PDF link for Hot Chips slides)

So they claim "No ISA" but this does not seem to be true -- they have "configuration stream" instead, which seems kinda like ISA but highly optimized for a specific chip model. This reminds me heavily of VLIW CPUs which also needed binaries optimized to specific chip type.