The Airstream factory never has, nor will they ever, use a method of repair that reminds us of a Disney character.
First of all, radiator or heater hose MUST NEVER be used, even as an emergency repair. That type hose puts a distinct "rubber" taste in the water, and if used on the input side, can also put that taste rather permanently into the water heater and or water tank. There are several types of high pressure plastic drinking water hose available, that can be used for repairs, but never rubber.
As a test, for yourself, pressurize a rubber water hose and leave it in the sun for just an hour, then put some of that water into a glass. You will find it to be warm, which is OK, but also smelly and if you taste it, I promise you that you won't drink it.
That type repair is a cheap way to cover up typical "freeze" damage. I would suggest that you measure the diameter of all the copper tubing that you can reach in various places, to determine the extent of the freeze up.
Airstream used 3/8", 1/2" and 5/8" copper tubing for the water system. If you find measurements that differ with that, then you have confirmed freeze up damage.
If that's the case, I would suggest you bite the bullet now, and replace all the tubing. If not, in time, you will experience failure after failure, that seems to never end, and will always happen on a trip.
If a previous owner repaired that trailer that way, I would suggest that you check other items for your peace of mind.
Does that trailer have rear end separation, bad axles, off brand (non Airstream) components added, silicon sealers on the exterior, signs of water leaks, bad shocks, worn out brakes, bad wheels, LPG leaks and the like.
Or, take the trailer to someone that can do a "complete" safety inspection for you, that will give you a report as to the integrity of "everything."