Two separate issues being discussed in this thread:
1) The ability to purchase a new ticket at a customer service counter anymore - this has been an ongoing trend by United to push all new ticketing to either phone or web channels and have airport personnel deal with that day's operations. I'm not saying I agree with the move in that direction but its been going on for years. IMO whenever you have a customer wanting to pony up some cash for your service you should close the sale. Not construct obstacles to them completing the sale.
2) The ability of UC agents to provide rebooking services. Doesn't seem like its anything new here either (since 3/3). Experiences and lines being uttered by agents all over the map. Some providing service, some being overwhelmed, etc. If United intended to reduce services offered in the clubs I would think they would reduce staffing. This is what should be the focus to determine if in fact there are service cuts coming IMO.