I'd just say: Careful about non-competes and potential trade secret violations. Regardless of their merits, if Google wants to take you to court, they could bury you in legal costs before it ever goes to trial.
Given I'm going to take a completely different approach that doesn't use anything proprietary, and non-competes aren't enforceable in California, I'd assume this is ok?
You should also be aware that as long as you’re an Alphabet employee (read: receiving WARN act salary payments) you’re still bound by any IP agreements you signed to start employment.
The non-compete isn't an issue but the "trade secrets" could well be. At the very minimum, make sure you and everyone who joins you is 100% clean for the past 12 months in terms of never transmitting or storing any work-related content outside of Google corporate devices/emails.
It will be ok, after you've spent millions in the court proving that it is ok. Shouldn't happen before you're a threat to them though, so maybe you'll have the money by then.