I think this overestimates the impact of a Clinton slot on elderly Dems*, and underestimates the impact of a slot going to a Palestinian speaker (in how many people care, how much they care, and in second order effects like headlines and narrative). * but NOT giving him a slot would be a big deal
It's not a trade like that. Uncommitted's offer wasn't so Harris would get something from Uncommitted qua Uncommitted, it was a way Harris could have quelled a concern raised by its membership. The return is goodwill! Not guaranteed, not specific, just a way to try to get some folks on side.
If both parties went off the rails into paranoia, voters in both parties would call the other party a danger to society. But if one party went off the rails while the other remained within normal range, voters in both parties would still call the other party a danger to society.