Locking bins seems unlikely - it adds complexity and mass to the plane, as well as something that can (and will) break, usually in the most inconvenient way: trying to do a fast turn, luggage bins locked on their own and now you have one plane full of angry pax who won't get off without their bags, and another plane load waiting to board and angry that their flight is delayed. And it has to be engaged at evac time and actually work then, and it still doesn't deal with the bags under the seat.
In a lot of my experience, people will more likely do the right thing if you make it easier and more obvious how to do that, than to do the wrong thing (some will do the wrong thing no matter how hard you make it). If people are lining up to exit and you're in a window seat, it's easier to pull your bag out from under the seat than to get to the aisle. If you're halfway between exits and already standing up, but people are leaving one row at a time (like for deboarding), it's easier to pull your bag out of the overhead than to get to the exit. So how do you get people off the plane faster so there's less temptation to take bags with you?