Having removed the tailplane on a number of c150/152 aircraft usualy for cracks in the rear spar casting i,v come to the conclusion that cessna are trying to smoke screen a slight weekness in the back end .
I dont think that it is a problem that should alarm us and that with normal maintenance eny cracks will be picked up but if the issue can be clouded then if a problem should happen the lawers have some thing to hide behind.
In short i think that product liability is at the bottom of all this ,about 10 years back piper issued an SB stating that you should never turn the prop by hand ,then if some one turns the thing by hand with the mags on and gets hurt pipers lawers can use the SB as evidence in court.