I recently read that the Linux Kernel 4.9 release introduced support for ARM powered devices including the Raspberry Pi Zero. That got me thinking and brought me to the realisation that there's a huge gap in my knowledge on the effort people go through to get operating systems running on the Raspberry Pi. I'm extremely grateful to mpthompson and plugwash for Raspbian although have no real insight on the number hoops they had to jump through.
What is the significance of the most recent Linux Kernel release to the O/S end users? In my limited understanding it appears to be that when redhat or slackware release a distro based on linux 4.9 it will have the armel support built in but they will still have to go through a packaging and testing exercise to certify support.
Is the main advantage with the most recent kernel that fewer custom drivers have to be written, tested and packaged in the distros for getting them running on a Pi?