Yes.
But politics is a game, a long term game. IF she wants any future in the party, and I'm sure both she and her DNC overlords want that, she had to fall in line just like mayor Pete, Nervous Amy, and the rest.
Which, imo, also convenient explains why Pocahonky hasn't endorsed Biden. She has no long term future as far as the party is concerned. Actually, neither her nor Biden do. That's why it was going to come down to one of them being the nominee who is sacrificed in this fall's election. Bernie? Sacrificing him in a general election serves no useful purpose now, just as it didn't in 2016, and in fact would be harmful to the party. Easier just to rig it against him, because the DNC doesn't want a socialist anywhere near their party's nomination.