Gills?

Nope, gills are still there. Check out the video in Jukerde's Godzilla Glory Shot in Smooth Slomo thread. It appears the video is lightened up too, and you can see the gills are present. 

I don't think they're gills, they're on the front of his neck as well so there'd be 3 sets total.... One on each side and one in the front in kinda like a triangle order which seems odd......

^Maybe in front of his neck is his neck pattern design.

And also its just hard to see his gills in the new tv spot ik