I'm definitely rooting for Rivos on this one. I have former colleagues at Rivos, but also apple is a litigious bully. It's also super hypocritical of apple - it was totally ok for them to go after recruiting talent from the likes of Qualcomm etc when they were building up their hardware.
IANAL so I don't fully understand the legal merits of this case. That said between Nuvia and Rivos it seems like the pattern is pretty clear: if you want to eventually try to do your own chip design startup, don't work at Apple.
Apple and Adobe also used to have a mutual no-headhunting policy. And speaking anecdotally I don't think I've ever heard of someone working at both companies during their career even today.