I think that is a mistake many people make when first learning about rose rosette disease. I nearly made the same mistake but luckily discovered that new rose growth is often a reddish color. Then I did have the "Witches Broom" growth develop on a few roses. I was successful in cutting that out and they seemed to recover. However I did loose a couple last year to some type of root rot, that just turned the entire plant black and killed them.
