I can confirm that Kubota has done nothing to address this issue on the new 2017 BX series tractors either, as I shredded my fan in the 2nd week of operation. Being somewhat mechanically inclined, and knowing this issue as existed for years, I thought for sure that by 2017, Kubota would have addressed this $10 part replacement....right? Nope...alas, these fans are still a) vulnerable to sticks and b) attached with 2 completely hidden bolts that are impossible (literally) to access without tearing half the tractor apart. By half the tractor, I mean the ROPS, seat, battery cover, floor, all knobs (one of which required a torch to yank off), fender and light connectors, as well as the front and rear connectors on the main drive axle (or alternative: remove the hood, unbolt the motor, and slide that assembly forward....but then you need a lift, or strong buddies).
Anyways...I went the a) remove the back of the tractor b) cut a slot in the fan using snips which allows it to slip over the shaft without removing the shaft (this is where I deviated from the service manual) and c) bolt back on using what little play you get at the front of the axle to get a 90 degree universal socket onto the back of the inaccessible bolts and torque them down (a little).
Not cool Kubota, not cool.