As you said, it is all conjecture at this point. Also, we don't really know if Bernie is actually in favor of his own agenda or if he is simply playing sheepdog to progressives to keep them voting for the neoliberal Democrats as "lesser evil". He doesn't need much pressure to fold up his tent in the middle of a campaign where he has a large following and practically unlimited fundraising potential.

If anyone believes that Biden got from almost dead last to frontrunner in polling legitimately in a couple of primaries I have this great bridge to offer them. If Bernie were actually a serious candidate he would have been shouting foul from the rooftops. His fear of becoming a second Nader doesn't let him off the hook for how he hoodwinked his many devout followers.