Currently the All-In guys (David Sacks, Jason Calcanis, Chamath, etc.) have been endorsing and fundraising for RFK Jr. Will any publicly switch to Vivek by October 31st?

Two hosts required to endorse Vivek to resolve YES.

Current list: Chamath Palihapitiya

They should state that they are endorsing Vivek, though the word "endorse" isn't a requirement. It should be a statement that clearly indicates they support the candidate beyond mere curiosity or liking their ideas. However, it doesn't have to be exclusive endorsement i.e. they could endorse Vivek without withdrawing their endorsement for RFK.