I'm feeling a lawsuit eventually going all the way to the Supreme Court: Laptops United! I feel they are starting to edge into the realm of personhood, carving out their own space on airlines, and taking affront to drinks being spilled on them! Laptops in the ICU (geek squad) or sadly having a brief memorial before being interred in the Compact Fluorescent Section of the dump.
I think if the airline offers "reclining seats," then it is okay to "recline" them. Although it is always nice if people use common sense and good manners, you don't always get that with the public. Surely the airlines don't expect seats to be reclined "only if no one is sitting behind you."
I think you can HOPE for good Laptop Using Conditions on a flight, but you can't assume it. Any more than you can assume you will have a peaceful flight with no crying babies, or a smooth flight without turbulence, or a relaxing flight with no one sitting next to you or in front of you. You should assume Sardine-like conditions, and be thankful if it's better than that.
I suspect the airline will now need to make a ruling on this, perhaps with the flight attendants making the call on the field, subject to further review with instant replay. Meanwhile dissatisfied fliers can fly "under protest." OR, they can try to kick dirt, drop drinks or have tantrums until they get thrown out of the game and the flight is diverted.
I think the devices will be banned.