It is not a big deal. The drive shaft slop is the sum total of all of the clearances in the ring gear, spider and side gears, splines, birfields and hubs. If you have a locker, it usually increases the slop.
I just installed an ARB in the front of mine. I checked and rechecked the backlash and preload many times before I installed it. While reassembling, I noticed there was quite of bit of play in the driveshaft. It is the same way in my FJ80 so I didn’t worry about it.