I do not understand your comments about an echo statement. An echo will not put the text where you want it - it will put it wherever it feels like it (if at all). You need to assign the text that you want output to the $template_hook['profile_tabs'].

What does your template "bbebs_memberinfo_data" look like?

I've already written to the author of this tutorial, but received no answer so far. If he is no longer around or does not want to actualize the firstpost with the information already presented in this thread, I will post a new version myself.

Good on you. An update is definitely needed.