Some interesting points!
Michael Paoli writes:
Well ... :-) I think there definitely still are reasons to have /boot as a separate filesystem. Some may not be relevant, or as
You have lots of good reasons already, but a couple more:
o Multiboot systems: you can have one shared /boot that all the systems use, rather than the confusion where you have the /boot files owned by one of your installed systems, and the other systems all need to somehow install their kernels onto another system's root partition (like the way grub2 wants to work).
o Related to your point on being conservative on filesystem type: on a portable disk or SD card, you can have /boot be a filesystem that any OS can write even if the root is ext4 or some other Linux-specific type. For instance, on Raspbian, it's handy that people who need to customize a headless Raspberry Pi but don't have Linux can put files on the VFAT boot partition.
...Akkana