I think you are talking as if democracy matters to the power establishment. They don't care if Clinton or Trump are POTUS because they are both neo liberals and it is Neo liberalism that has delivered power to the establishment. Sanders was talking as if he might want to shake things up a little bit, maybe represent the interests of his progressive voters, remove big money and corporate power from politics - no way is that going to happen. It might be argued that with more votes, Sanders would have been the Democrat nominee in 2016 but the truth is, the primaries were rigged by the DNC, voting was corrupted to ensure that the primaries were won by a pro establishment figure - everyone's talking about Russiagate - what about Demgate - this one is clear cut and not based on supposition and joining the dots and repeating accusations until people stop asking for the proof, Demgate is based on court room testimony and it genuinely affected the outcome of the primaries and quite possibly the election.
If democracy mattered to the establishment, they would have whipped up public anger about this outrageous corruption and Hillary and the DNC would be wandering the political wilderness for a decade looking for a way to regain credibility with the public again.
I like your analysis and in a rational world where democracy was valued, it would be bang on but there is nothing rational or democratic about the 2016 election process or outcome in my opinion. Consequently I don't see the DNC putting forward a genuine change candidate any time soon, regardless of whether that is what people want.