We've known about silicene and germanene for a while, the question of their stability free standing is still open. But because their application primarily lay in electronics the goal is to grow a silicene or germanene in place, on top of some inductor and use it as is. Its hard though, you need just the right surface with just the right AVD settings. Basically you do a few thousand simulations to figure out what might work, then you lock a grad student in a lab and have them try to grow it.

We knew it would likely be possible to grow, but how easily and what final properties it would have (due to interactions with the surface it is grown on) weren't entirely known. Also keep in mind this is one of a dozen different possible technologies for building future devices with.