I know that at coffee machines in each of the eating sections, there is a hot water dispenser that one could use to fill a container with hot water. I used it each morning to make a cup of tea for myself. I brought my own tea. Now if you are more of a tea "traditionalist" and prefer boiling water, that might not work. But I do believe the family suites have a microwave, so in that case you could probably heat the water to boiling using a microwavable tea kettle.You can request hot water for tea at the Bayliner dinner.
A kettle is not a common American thing. Hot tea is really not a big thing here. I don't know anyone who has ever owned a tea kettle and have never seen one in American hotel. Not even sure it would be easily found in a department store here. I have never seen one for sale. If it is something you need you should definitely pack it.