While Ryuutaro certainly didn't need anybody's acceptance, he was still rather glad when Reborn reacted positively to his offer.
As much as he disliked the entire Vongola-thing, he wanted to somehow contribute to this. It would be a bit more like he was actually carrying his own weight.

As the boxes show up, Ryuutaro said nothing and just watched. He had no real idea of these things, so he'd have to wait and see what happened and what those even were.