I am going to admit my ignorance here, and say I honestly don't know. I have friends that have changed their junk crossbow scopes for quality Leupold or Burris and had no problems. That said, rifle scopes are designed for large amounts of recoil in the rearward direction, and cross bows recoil is forward, when the string shoots forward and stops suddenly.
The best thing I could offer would be for you to contact Vortex Customer Service and ask them. If they say yes, and it doesn't void the warranty, I would be fine with it.