I did have a sore throat that felt different from a cold when I experienced the first two vocal cracking periods, but it wasn't extremely uncomfortable. It just felt like I had been talking/singing too long without drinking anything. It did go away in my case, but keep in mind that there are strains of the flu floating about and when I had it in Jan that was the worst sore throat I had ever experienced.
Since I'm on injections I can't really say if it's a side effect or not. You might want to read the prescription pamphlet and see if it could be a gel related side effect. As far as I know it's not listed as a side effect of the injectable (intramuscular) testostrone cypionate.
If it becomes bothersome, gets worse or stays around for more than a week I'd consult with my doctor if I were in your shoes.