I wonder if it's more trim based than year based? I did not even know that there was an hood insulation on TJs till I came on the forums a few years ago and saw someone's photo.
Probably connected with an option package. Both my 05 and 06 were Unlimited Sport, but the 05 had hood insulation and the auto dimming/temp/compass mirror, the upgraded stereo with a sub, and a soft top, and my 06 came with a hard top, no insulation, no sub and a standard mirror.