To be honest, i don't know, as i don't use the EXIF data from my camera.
After tests on my images, i can retrieve the exif data related to FILE and COMPUTED formats. Thx to tell me if all the data are saved.
I am pretty sure that imagecopyresampled, the GD function i use to resize resets the EXIF data related to cam. For me, it is not an issue. Before that, i was resizing my pix with ACDSee and the metadata were lost while editing.
I know how to retrieve the EXIF data from a picture with GD, i don't know how to insert data into a picture. If such a method exists, then, the exif data retrieved before the resizing can be reinjected after resizing. It is a way to solve this.