Meanings do change, but they should be looked at for the meaning when they were written. At that time, fruit of the vine very simply referred to wine. The cup after supper would have had wine. Looking at the scriptures we can clearly see that it was wine. As wine is what Christ used, we should also use wine without putting our human reason into it.
If we are given an element to use, told what should be used, that is what should be used. Red, white. Sweet, dry. Variety of grape? These are the things that make it legalistic when someone argues exactly what type should be used. Kind of like if someone believes only water from the Jordan would make for a valid baptism.
But Jesus says use water. He doesn't say water from the Jordan, he doesn't say spring, filtered, perfectly clear, etc. He just says water, so we use water.
Likewise, Jesus doesn't say specifics for the wine, but he most certainly says wine made from grapes. Just like we stick to water for baptism because it is the element we are instructed to use, we should stick to grape wine because it is the element we are told to use. Beyond that I would agree we get legalistic and overly so.