Getting hot water may still be available upon request ... I have not been on Amtrak since the pandemic began (and don't plan to be anytime soon)
On our most recent Wolverine trips (pre-pandemic) I was advised that hot water was no longer available in Coach. You could purchase hot tea, and just not use the teabag, but free hot water was discontinued. We used to bring our own teabags and instant oatmeal, ask the Cafe car attendant for a cup of hot water, and tip a dollar for the water.