I’m an slp. I don’t think it would contribute imo. The /b/, /d/, and /g/ thing is a phonological process known as devoicing. It has more to do with your vocal folds than your tonsils. Enlarged tonsils can impact a person’s voice resonance which causes them to sound like their nose always plugged. Enlarged tonsils during childhood can increase the likelihood of ear infections which can lead to articulation/language impairments later on.