When going to Adoy's Enclave for Neera's quest, I picked up the +2 squeaky leather armor. My Kensai is able to equip it and Kensai should not be able to equip any armor at all.
A Kensai seems to be able to wear most newly added armor, so far seen on the Protector of the Second from the tutorial and the Squeaky Rugged Leather +2 from the goblin cave in Adoy's enclave. A Kensai shouldn't be able to wear any armor.
One further thing: It seems the "old" Protector of the Second in the campaign is properly flagged, so Kensai can't use it, just the "new" one in the tutorial seems broken.
Comments
Expected Behavior: Kensai is unable to use armor
A Kensai shouldn't be able to wear any armor.