0-morale units behaved oddly prior to the patch already, tbh. Mostly, they wouldn't automatically fall back/rout when they were supposed to, but I've also seen 0-morale infantry launch an assault (and due to being high quality, actually losing no morale in the process :x)...
Disengaging also seems to not work reliably, sometimes I can, sometimes I cannot disengage. While this is actually quite reasonable from a historical POV (as a unit hotly engaged with the enemy would be extremely hard to control, probably unaware of what was going on elsewhere, and maybe not even aware how badly it was suffering at the hands of the enemy), the sheer randomness of it can sometimes be frustrating from a gameplay POV.
Other than that, I'm quite happy with the beta patch so far. Not sure if I'm just imagining this, but the AI seems a tad smarter, too, it now skips the firing phase when doing so would put it at a disadvantage (i.e. it'd take multiple defensive fires in return), instead using assault only, or not engaging at all but merely blocking with ZoC.
no truth - no justice
all false belief
blinded by morality
there shall be ... no peace