@sabzee,
From my point of view, things were quite "hairy" before and both are trying a new start, new ways and a hopeful good outcome.
I mean there was something there to start with or you wouldn't try again.
I think that he may have a fear of things going back to where they were "when, he deleted you" and he's biding his time that's all.
This isn't in my opinion about having another arguement by you bringing this up, this is about him ensuring things are going in the right direction and when it is clear that you both don't argue anymore, you are on track he'll add you.
I think he has an ego, but you do too otherwise, you wouldn't be worried about him not being a "friend".
At the end of the day, you both command respect for each other when you've reached that you deserve to be best friends to, therefore added.