I have an 07 24" towlite and it is a painted aluminum roof. You shouldn't necessarily have to replace the roof if you keep up on the regular maintenance that a camper needs.
As long as you check the roof for pinholes or damage it should be okay. Replacing would be a serious operation. You may want to give it two coats of Koolseal Elastomeric paint for metal roofs. It is a popular product for mobile homes.
Some Hi-Los had rubber roofs in the the early 2000s but they went back to aluminum. Which do you have?