The orchestra arrangement is continuing: Schumer and Jeffries are to meet with Harris shortly.
So rather than be the first to endorse, they will do their due diligence with a one-on-one and then come out together and unified. Does Harris come out with them for a photo-op, for the "hand in hand raised" opportunity?
I would not be surprised.
What does Biden do when he speaks about this transition? Does Harris and the party want to tweak policy? Does Biden support changes that Dem nominee wants? Give her reign to divorce from the absolute policy in place, or will she be tied to Biden presidency?