Seems like there's no way it's anyone but Kamala. Which I think is best at this point. Obama seems like the most significant player that hasn't explicitly endorsed her
https://x.com/GavinNewsom/status/1815168477562646858
I don't think there's anything in him not endorsing yet. He also slow played Hilary in 16 and Biden in 20. It's only been a couple of hours and it's probably prudent for him not to endorse just a couple of hours into this process.
Sidenote, I really truly hope she doesn't pick Newsom. I would prefer Whitmer or Shapiro, probably not going to be either, but it can't be Newsom, which means it probably will be.