I'm not suggesting that these sequences can "look forward" in time. However, consider that mutations are constantly occurring. These mutations shouldn't be dismissed as "junk" simply because they seem unnecessary now. In the future, they could become essential.
Over long evolutionary or environmental timeframes, these sequences may take on important functions, potentially becoming critical under conditions we can't currently foresee.
If such a mutation occurs, that sequence would no longer be junk. Until and unless it does happen, it's still junk. But it's silly to get hung up on the sequence, or on the word "junk", based on such a slim chance. What are you trying to prove here?
