I don't think they were "assuming" but rather betting on a win by republicans.

"Morgan Stanley held the lenders together, betting on the relationship of one of its then top bankers — Michael Grimes — and his client Musk, people familiar with the matter said. The bank led weekly calls to update the other lenders on X’s performance. Working together as a bloc helped avoid one single bank abruptly selling the debt at a discount."

Sounds like... collusion.