Will having tonsils out change singing voice?

It depends: If your tonsils are small and the change in your throat is small then the likelihood of it changing your singing voice is small. The bigger your tonsils are the greater the likelihood that it will change your singing voice. The reason is that your throat and nose is your vocal tract. The vocal tract is what determines "your sound". By removing tonsils you change your vocal tract and you can change your sound.