I don't see Coos Bay RailLink as " ...having a ton of business with UP... " or anyone else. Their line has many of the same problems as NWP, namely VERY unstable terrain to traverse, which will require LOT$ of maintenance. Virtually every bridge & tunnel will require upgrading or outright replacement. The line is also slow speed, and starts in Eugene with it's gutted yard & little infrastructure left from years of UP's neglect. From Eugene those double stack trains would still have to travel either South through the Mt. Shasta - Dunsmuir - Sacramento River Cyn. area, then the congested Roseville - Sacramento trackage to reach The Overland Route East. OR - North to Portland, then East through Columbia River Gorge.
The Ports of Seattle / Tacoma in the North, and Oakland / LA / Long Beach in the South already have much of the necessary Railroad Infrastructure, as well as HUGE local markets for imports.