Hello Kael,
I'm seeing a bunch of newbies on the boards that have their email adresses displayed instead of their forum name, and I don't think there is a chance to avoid that during the account creation.
It's all these people from big corps like Nasa or JohnDeere of which the emails are getting exposed, and many more. It is due to the change of the looks of the forum or whatever else just happened couple weeks ago. I don't think any of these people would let their email happen to be public if they had a choice.
I do need to create a new account, so that's why I'm asking. I highly doubt the solution you have provided is gonna change the already mentioned default forum name or Username.