Okay, after this, I give up. I don't know if you're being obtuse just so you can "win" or if you really don't get it.
If the statement "I will give you all the money I have." is different from "I will give you all the money I ever have." then so too are the following statements different:
"I am proficient with all the martial weapons that exist."
vs.
"I am proficient with all the martial weapons that will ever exist."
One is a snapshot. The first says: Set W contains all weapons that exist. Set P contains all weapons that I am proficient with. Set P contains all of the elements of Set W at time T. If, at some future point, the elements of W change, we can no longer guarantee that W and P are equal.
The other is continuous. It says Set W contains all weapons that exist. Set P contains Set W. Therefore, by its very nature, if Set W changes, that change is reflected in Set P.