I have (or had, I guess) an 11 year career in Fortune ~100 finance and healthcare. Agreed on all points. However, they're already experimenting with Debian, Ubuntu LTS (just not 16.04), kernels, custom AMIs, and different Docker versions. It's not a stretch to imagine they have the ability to deploy a back-ported kernel, or build and/or use an AMI that includes one. Also, HFT practices (or lack thereof) are far from the staid enterprise practices you may be thinking of.