IIRC it was to do with aero on the nose. Dodge called it their 'Race Car' for that year... I think, lol.
Because what year/races did teams cut off the fronts of them and used the older noses? NASCAR allowed it, Dodge wasn't happy about it.
If I recall that whole deal with the noses was more around 2005-2006, as late in the 2005 year some Dodge teams experimented with 04-spec noses instead of the Charger Noses at Homestead, and several, such as Petty and Penske stuck with them on the downforce tracks until Dodge told them to knock it off and run the Charger bodystyle.
The main issue with the first Charger nose was while the anteater shape was great for downforce in clean air, it also sucked trash into the grill easily, and wasn't as good in traffic if I recall. Hence why Dodge overhauled the nose in 2007, which has a profile more similar to the 2003-2004 spec nose.
Of course in 2007 Evernham then went back to the 2006 style nose, but that was more the fact that they had somehow lost all of their data on the new nose, and as such were forced back to the old nose, but of course since that "package" hadn't been actively developed since the end of the 2006 season, it further hindered the teams performance in 2007 and was one of
many reasons that Evernham's season was such a "dud"
Petty also used the 2006 style nose starting mid-season as well, as they were aligned with Evernham, so made the switch around the same time.
Now on the subject of the 2004 nose conundrum, I'm not as certain, but I'm guessing since they had already planned on discontinuing the Intrepid, and the Stratus would follow soon after, as well as the Charger being another year out, they just slapped something together to run so their factory teams could still race in the transition..