There have been two DLC updates this week, one for the Hudson Line Extension and the other for the Montana Hi-Line routes.
I see in the announcement section that there is no mention of the Hudson Line Extension being updated, but only the Montana Hi-Line. The Hudson Line was updated on the 19th, and the Montana Hi-Line on the 20th, according to the dates in my Railworks Content Routes folder. I'm pretty sure that I read about the Hudson Line Extension in the announcements section. Perhaps DTG released a patch for the Hudson Line Extension and then decided to take it down for some unknown reason.