They Lincoln Project guys even said they'd be backing Bernie if he was the candidate simply because Bernie respects America and Trump doesn't. Whether or not that's actually true about them backing Bernie, it means Biden doesn't owe them .
My bigger concern is the waive of endorsements Biden has gotten from ex-military/national security officials. Biden has been completely silent on how neoconservative his foreign policy is going to be, and I'd be surprised if that wasn't by design.