We'll have to see... I could understand if they limited it. It would make sense that not everyone could get close enough for that sort of thing. And just because Akane can make friends easily doesn't mean the others would be at ease with her. Remember that Aoi was the limiting factor here, despite their closeness. I suspect she would have trouble merging with Wakaba and Himawari. Those two will probably be better suited to each other. The end may require a four-way merge, however.
I'm also expecting an Akane-Rei docking at some point. It's totally a necessity.
