No. Only if you're putting it on a trailer.
Flatowing with the T-case in neutral is the same as driving in 4wd. There's no connection between wheels and transmission, but there is still a mechanical connection between the front and rear axles. You can put the tcase in neutral, but drop the front driveshaft as well.
I just double checked with the 231 sitting on my workbench in the shed. Even in neutral, the yoke for the front D.S. and Output shaft spin together.
but the jeep transfer cases have an oil pump on the output shaft of the transfer case my dad has been flat towing jeeps since the mid sixties and has had no problems after flat towing with the drive shafts hooked up. the pump spins while the t case is in neutral the pump still spins lubricating the case as it spins