Well if Thorpe's introduction to them is anything to go by, they'll have Coca Cola on site for the first few weeks to iron out what ended up being numerous teething problems, it's after that where we'll probably see the issue
Can't see Coca Cola being onsite for two weeks to support 7 Freestyle machines (or 14 if Towers are generous and double up on them at the stated 7 locations). These machines are tried and tested when looked after properly. Aah "looked after properly" - might have stumbled on something there.
I can see the issues being the concentrate syrups running out & therefore giving an inconsistent choice of soft drinks across the park. (The syrups are not topped up manually, you have put in a complete new box. Given Towers desire for cost-cutting the daily checks will just be to open the machine & rattle each syrup box to check there is some product in there).
The machines also have to be kept topped up with ice through the "roof" of the machine. This will require F&B staff to fill containers (buckets?) with ice from their ice units ice maker & go and tip it in the Freestyle machine. They'll need a small stepladder (3-4 steps) to do this safely - Towers can't risk any H&S injuries from lifting / over-reaching with heavy buckets of ice.
Also, I can see that a "certain element" of guests will take their frustrations out on the machines when it does not dispense product as they are not using a chipped mug - either bought / re-activated on the day. You only have to look at the state of some of the other vending machines on-park.
Finally, it would be good if the machines dispense chilled water to guests with a valid chipped mug - that would allow them to rinse their mug, then get their drink refill. (The Freestyle machines at Universal did, for a couple of years, dispense chilled water and ice to anyone - i.e. no chipped mug needed. They have since switched this feature off as they were clearly losing too much on the sale of ice cold bottled water. You can only get any product from the machines with a chipped mug now).