Ah, now I see what you are getting at
No, you do not need to loosen the pole in preparation for rain or while its drying.
My poles (I have three tent ends) were set once when we first bought the unit. I check every now and then if I need to adjust, but so far so good. There has been no stretching.
Now, with a brand new Roo or Shamrock camper, the instructions that come with the unit will state the seals in the tent ends need to be seasoned. They need to get wet and expand. I am not as familiar with Surveyor or other brands.
By the way, what camper do you have?