I will see what I can do. In the mean time you can edit the language string called _user_activation_succeeded and add something like the following:
Congratulations!<br /><br />Your account has been successfully confirmed and activated. <br>Please scroll down and click "Set Avatar" to complete your profile setup.
Congratulations!<br /><br />Your account has been successfully confirmed and activated. <br>Please scroll down and click "Set Avatar" to complete your profile setup.