I don't understand why people want a feature showing who is playing grouped and all that. The only things I can think of are for people to talk shit about bad pre-mades and good pre-mades, which they do plenty of now if they figure out there's a pre-made.
Premades have a higher tendency to gank/roam to each other's lanes, in my experience. An opposing jungler with either of his premades in the bot lane will significantly increase the likelihood of the jungler camping bot lane for instance. As far my experience goes it's a very good indicator of the other team's landing phase strategy.