There should be enough work, but the difficulty will be persuading a company that the staff add value to them for the amount they cost. It's difficult to calculate how much value on concourse staff bring to a business, and how much, if any, additional revenue they bring in.
The bean counters are always looking to save money, and should the employees not sell sufficient tickets when they are out and about,t hen I do have concerns for the future, as they will be one of the easiest roles to cut. Even in the best case scenario, I suspect that those who retire or leave just won't be replaced.