Does re-tipping a cartridge change specs?

Anything what is in combination with generator, wiring ...won't be changed. Improved specs you can get with a different diamond (side walls) in the frequency area. Mostly these are better (manufacturers rarely use "expensive" needles), probably better Azimuth (or a more correct one, this depends on quality control) and maybe a different VTA / VTF.

I had my Denon DL103 re-tipped with a stylus capable of higher resolution and the cartridge stepped up to deliver a more detailed  sound and much better imaging.

The "spec" stayed the same, but there was definitely a change in performance.

Regards - Steve

 re-tipped by a professional with another micro ridge (sapphire/boron)

Sapphire or Boron ?

Looks like it was not only re-tipped, but completely re-cantilevered - right ? 

If the original cantilever was Boron and now you have Sapphire (or vice versa) this is not a re-tip. Someone refurbished your cartridge with different cantilever/stylus combo.