I have a 3400x4303 JPEG and when I try to export it as a rotated georeferenced TIF the TIF that is 509x578.
Because the TIF is rotated I don't expect the resolution to be the same but I certainly don't expect it to be smaller.
In the Export dialog I can manually set the Raster Size but can't ArcGIS just autocalculate what the new raster size ought to be if the resolution of the source image is to be maintained?
In the environments tab for the tool, you can specify the cell size, otherwise it gets set to 1/250th the image width