Yes, there should be swastikas on the fin. Revell, like a number of manufacturers, choose not to include them on their decal sheets, as they are still banned in some countries.
Some decal producers make the swastikas in two parts, but, I think that in Germany, even this may be taboo, and I'm guessing that as Revell USA and Revell Germany share distribution of moulds and certain kits, they are playing it cautiously.