This makes me wonder. What if you had a -choice- of making your vote public?

Perhaps a percentage of the voters, those who fear no public repercussions, would choose to make their own public.

What would be the implications in this situation?

You can do that today. However, no one can verify you are telling the truth. That is the key point.

If you can choose to make your vote public then you can be coerced to make it public.