For example if there is a high speed and low speed CAN bus or just one really does not matter cause of details about how it works.
It matters a lot. Typically, there is a gateway (in body or chassis controller) between the two (or three) buses. It puts some messages from the controller bus onto infotainment bus, but not the other way around. It's done specifically to prevent infotainment systems interfering with workings of the car.
If Jeep has everything running on the same bus, it's incredibly stupid.
That is a bit over simplified. In practice more is passed, but for example the ECU ignores based on rules like RPM above X, TCM not in P, and so on. There is pressure to move to a single high speed bus and modules that pass messages based on priority and time.
It matters a lot. Typically, there is a gateway (in body or chassis controller) between the two (or three) buses. It puts some messages from the controller bus onto infotainment bus, but not the other way around. It's done specifically to prevent infotainment systems interfering with workings of the car.
If Jeep has everything running on the same bus, it's incredibly stupid.