If your question is just about dropping processed, sweetened drinks I see no issues with that. On the contrary, your teeth will thank you . Make sure you eat a well balanced diet with fresh fruit and veg, whole grains, healthy fats… And listed to your body, it will tell you what it needs. Enjoy the journey.
They didn’t have to come back and tell you you were right; could have just bought it elsewhere and avoided you (out of shame for their own ignorance) so I consider that a win at your end. You can totally own that!