Yann LeCun to depart Meta and launch AI startup focused on 'world models'

I'm interested to understand how this works from an IP perspective. This guy is still employed by Meta but is actively fundraising for a new competing startup. Presumably he will have negotiated that Meta forfeits all rights to anything related to his new business? Would be interesting to hear of people's experience/advice for doing this. Or are there some legal entitlements he can avail of?

Even if it’s Meta, they don’t want to antagonize LeCun. Also they all know it’s a small circle of people that create value. I will not be surprised if meta itself invests in his company and get a share.