I'm not sure it's random, I'm thinking more along the lines of them testing things.
They weren't that random before to begin with, and I'm now seeing very, very few wanted type 6 and 7s, when they used to be almost all wanted, and now pretty much every Cobra is wanted. And just this morning, tons of wanted Eagles, when Eagles used to be exclusively bounty hunters.
On that topic, I've also noticed some very weird behavior, with bounty hunting ships flying as one big group, and having the same reactions, like stopping or turning to a direction all at once. And I'm pretty sure I've seen several pirates do the same. They wouldn't be stealthily testing AI for the wings update now, would they?
Here is one such group, consisting of a bunch of Cobras, an Eagle and an Anaconda. They just flew around together in a tight formation: