The British millennials value traditional travel agents more than American millennials, but still a large majority have moved away from it, which shows in the number of shuttered high street travel agent store fronts over the last decade or so.
This is a good indicator of how millennials could still be retained by the organized hotel sector, though of course catering to the specific needs of this demographic is still important.
There are hints that while millennials have largely moved away from traditional travel agents, there are use cases that require them and sub-cultures that will continue to use them one way or the other.