I'd get it to have it. It's way better to have the option on the off chance you need it.
My first trip was the 4th of July at a 30/50 amp campsite with 550 spots. The only place I could find, since I showed up on Friday was a 50 amp pull thru. No matter which way you turn the 30 amp plug it will not fit. I took a drive down to their store and no 50m-30f adapters (but they had a bunch the other way). They went in the back and fount 1 adapter, which was misplaced. Since it was 100 degrees out and my spot had no shade, this was a necessary item that I overlooked when buying accessories. My wife probably would have shot me if I came back empty handed.
Buy it and store it with all of the possible adapters you need. It saves the stress and the time out of a trip to procure one.
2008 Toyota Sequoia SR5 5.7L 10k tow package
2017 Rockwood 2702WS
Equal-i-zer 4 point, Prodigy 3 brake controller
2016 nights camped = 11