Trust me, no scientist at Draper spent months on this. It would make some damn sense if they had. It reads like a summer intern's wide-eyed ramblings after they just read about things other cubesats have done, but before they considered any of the actual engineering issues.
And sometimes, you end up with a random /.er who, though the satellite he's working on is only going to low Earth orbit, sees the potential of applying the cubesat fast/cheap/high-risk philosophy to interplanetary missions, had already quantified the problems with power generation at Jovian distances from the sun and the resources required to communicate with a miniscule power budget, and even went and read about the possibility of common materials surviving unshielded reentry a few years ago when the chipsat idea started making headlines.
There's real potential for using cubesats beyond Earth orbit. Lots and lots of people have noticed this, and they've generally also noticed the same set of problems -- power, cold, communication, and radiation. There are possible solutions to each of those, but they come with major costs and the probe described and drawn in the article incorporates none of them.
The aerodynamic entry idea is utter nonsense on that moon, though -- what passes for an atmosphere on Europa would qualify as "ultra-high vacuum" in a laboratory. It's about the same density as what the ISS is orbiting through right now. There is no structure in existence that could decelerate enough in that atmosphere to land gently. The terminal velocity of a flake of monolayer graphene is comparable to rifle muzzle velocities, and functional circuitry is a few orders of magnitude heavier than that.