Do you need it? No. Could it be helpful? Maybe, though only slightly at best. By that, I mean that it's feasible that it'll add a few percent to your catch rate. If you woulda caught 100 on such a trip with a mid-priced rig, just maybe you could stretch that to 103 or so with this one. You'll never be able to prove it. But an extra few inches on a cast, or a little better feel when mending, etc., has to help at least a little.
The truth is that nobody needs top of the line rods. It's a hobby, success is ultimately meaningless, and there's nothing to measure against anyway to prove success or failure. But all of us want nice equipment. When in a fly shop, we ogle the nicest rods, maybe pick em up and give em a wiggle, and tell ourselves "someday". I can tell you that when someday comes, it is enjoyable. You'll later ogle more rods, but that one becomes a treasured possession. Even moreso if you got it for a trip like this. So if you got the dough, and see yourself doing it someday, today should be that day. This kind of trip is the perfect incentive to pull the trigger on such a purchase. It makes it even more treasured. You'll always say you got it for this trip, and then trigger memories of the trip.
A side note, or heads up, or whatever. I just got a TU flier asking me to become a life member. It's $1200 or something, but it comes with a Sage One outfit. 9' 5 wt I believe. If that's the rod you'd want, and you don't already have a life membership, it's something to consider. If I were gonna spend 7 or 8 hundred on such an outfit anyway, I'd probably throw a few extra hundred on top and get the membership. Would be an easier sell to the wife as well. 🙂