they never mention bags being left on evacuation.
Well, they mention "all belongings" but people tend to interprete things differently these days... If they do not say "bags" explicitly, bags are fine. It is like (no)smoking and e-cigarettes...
Do the other manufacturers have a similar failure rate? or is this a peculiarity of GE's design and manufacturing processes that make their engines vulnerable to these types of failures?
Basically the rate of uncontained failures is about the same, but as numbers are low, statistics are not very mature. Of course there are subtle differences, if you split your compressor in 3 (LP, IP, HP) each of them is smaller and hence stiffer, so critical speed (resonance of bending and rotation) or margin to critical speed is higher, hence more tolerance for cracks or manufacturing flaws. On the other hand your lubrication system gets more complicated if you have 3 spools, so that creates additional failure cases.
Compared to 50 years ago, jet engines are incredibly reliable.