I believe that they are going to make more spawns like this, they just started with 3 per island.
This will generate more higher level kernels then could be farmed previously on alpha, simply because you could NEVER get a 4th level assault or a 5th level light bot. So from 0 to rare is a huge increase. Also the Alpha I NPC farmers will be getting level 3 assault and level 4 light kernels more often, because again the random spawn, not the elites, can be a 1-2 levels higher.
Its more probable that there were too many grand observer kernels being farmed for the rate the devs felt was appropriate for learning research that way. First the Artifact nerf, but then there were too many beta spawns still, to they had the choice of reducing them too, but they took the make it harder to kill AND reduce the kernel drop rate to make it less profitable to farm them, but still f'n dangerous.
It was the same arguement with the 50% drop rate on normal bots too. The message is clearly that T4 is the 'top end' equipment and will be so for a long time still, and there are just too many producers getting access to them. If someone like me actually reaches the end of the tree, me as in Alpha-dwelling carebear, before the next tiers of modules become available, then the research was too easy.
It's a choice here, and they'll probably do this too, if T4 starts getting to easy to obtain, they'll nerf the norgalis again. Dev's will find a way to keep it rare, they have to, at least until there is another set of stuff to get.