Yeah. Nothing new here.
Why? Because it doesn't stretch. For a case to stretch, the pressure has to be high enough to glue the neck of the case to the chamber while pushing the head back and/or the mouth forward. This doesn't happen in small, straight walled, low pressure cartridges.
So it will shrink just a little bit each time it's sized, as would rifle cases, if they didn't stretch at all.
You actually trim this caliber?
How short is dangerous? Well, depending on who you talk to, you can safely shoot 40SW out of a 10mm handgun. A luger case will never get short enough to even compare. To others, the world will end if you try to shoot a case that doesn't headspace perfectly. Now shouldered cases can cause problems with improper headspacing, even in a pistol. I've seen case head separations in .357 SIG, resulting in stuck cases, even with factory ammo, due to improper headspacing. But never heard of that happening in a straight walled pistol caliber.
The sticklers will say something like this: "My reloading manual says that you can trim 0.02" when max length is reached. Therefore, the minimum length of a case is 0.734". If it's shorter than that I'd toss it."
So take your pick.