Amazon made a special version of Alexa for hotels with Echo speakers in their rooms Order room service, request housekeeping, or play some tunes June 19, 2018 https://www.theverge.com/2018/6/19/17476688/amazon-alexa-for-hospitality-announced-hotels-echo
Alexa is not a "requirement". Hotel guests can make a request to remove the device from their room (mentioned in a different article):
With Echo in Hotel Rooms, Amazon Can Now Track Your Travel Habits Amazon (and hotels) now have the option to collect new forms of data from people. June 21, 2018 https://motherboard.vice.com/en_us/article/vbqk4x/amazon-echo-alexa-hotel-room