I know that the Coast Starlight had WiFi when we took it in 2017. But when we last rode it in February 2019, I asked the sleeper attendant if I needed a password for access, and he said the WiFi had been discontinued just a few days before that. He didn't know why. I also recall that when we rode in 2017, my son kept going from our sleeper room back to the business class car to sit, because the signal was stronger there.
The wifi access points on the Coast Starlight were just consumer-grade Verizon hotspots -- the kind some people carry around in their pocket. It's not any faster than just tethering with your phone, and has the same limitations. I remember one trip I took on the Starlight, someone had actually hacked the access point and renamed it with a funny message if you checked its user interface.
Having a Starlink dish in every car would be nice but hard to implement as it would need to have a place to mount it that let it point upwards unobstructed. i.e. they would have to hack part of the roof out. I suppose you could get away with one dish hacked into the baggage car and then mesh network it to access points in the rest of the train. Spectrum usage would still be an issue as if you use unlicensed spectrum, some person firing up their own hotspot on that frequency would screw the entire train. (Also Starlink doesn't work very well in moving vehicles right now, but that should improve as constellation density goes up and they release dishes with better tracking and suspension).
People who can work from remote generally like long-distance trains if they have a good data plan on their mobile device that they can tether with. Once you get them to try it out, they actually appreciate it. A roomette becomes an office on wheels. The dog slow speed of Amtrak long distance trains won't help anyone though who have to make their retail or physical labor jobs where remote work is not an option. They want to do other things on their days off than sitting on a train, even if they actually enjoy the train. The train needs to *at least* be faster than driving on the interstate.
I take the Coast Starlight fairly regularly and like to take friends with me to show them how nice the trip can be. Speed is their number one complaint, followed by the rough ride on the poorly-maintained segments. They did appreciate the Pacific Parlour car back when they still existed -- they were impressed by the big comfy chairs.
You could even keep some of the slow segments if the bulk of the route could be gotten up to 110mph. Salinas to Paso Robles is the part that could be most improved (not much scenery, relatively flat/straight right-of-way, crappy-*** track).
The worst part track-wise is the Elkhorn Slough where the tracks are literally underwater at high tide sometimes. I gotta admit I enjoy that though as the train sloshes through, since there's plenty of great wildlife to watch while the train temporarily turns into a boat.
