It's great to see that there is an increase in engagement as evidenced by the explosion of "Do you want to be my friend?" threads and posts, however, it feels like it may need to be contained a bit, as there seems to be an increasing amount of these posts in multiple sub forums.
I'd like to suggest a short term and long term solution.
Short term:
Make a special sub forum to contain those posts.
Long term:
Set up a "match making service" for learners where they specify their: Japanese level (approximate JLPT level), times of availability, areas they want to study.