You left out the option of your new code living in the same namespace: to extend and wrap and deprecate stuff in one module.

Then you have all your code proximate and can keep your users and push them toward the new code. In your case it seems the pushiness may be tolerable since users will be attracted to the better interface functions. It also leaves you in a good position to refactor and reuse.

Coming up with new names for functionality can be a pain.

Wrappers are a simple way to extend and abstact existing code. I think your point regarding wrappers is valid but I feel that you are viewing them too negatively in this situation.

Be well,
rir