Yep - the 337/02 aren't listed for P3D - just FSX and 2004. But if that is all people have or care about, or don't mind that they may not be able to have the plane in P3D, it's all good.
The P-38 is listed for both FSX and P3D... (hint hint)
Bruce and I took the 02 up for a flight from Danang up north along the coast and through the mountains back for a landing and it really is a nice plane. One thing - it took us probably almost 30 minutes to figure out that all you do is open the door and click on the stanchion to get rid of the tie downs, ladder, and such. You just click on the accessories to change them or make them go away. Couldn't find that bit of information anywhere!
But for some reason, FSD does have a lot of their planes listed as for FSX and FS 2004 so buyers do need to look closely if that matters to them.