It would make a difference to some, for sure, but would it have a significant wide-spread effect? I sincerely doubt it. A lot of people seem to be of the opinion that transphobia is always a symptom of ignorance, but that's simply not the case. As someone who grew up in a very bigoted environment (a place where racism, sexism, religious intolerance, homophobia, etc. are the norm), I can tell you that it's not usually the case that bigots simply "don't understand." They don't want to. They choose to ignore information that contradicts their pre-conceived opinions, even when it's staring them straight in the face and you've confronted them with it 'til you're blue in the face. There's a lot of willful ignorance in the world and people who simply don't care about groups they're not a part of. It's a sad fact of life.
I'm not saying we can never make a difference. Of course we can. But it's not a simple matter of educating every bigot we come across.