Has a separate boot partition ever been the installer default? I know every time I have installed Ubuntu in the last few years, it doesn't offer to set up separate boot or home partitions -- those are allowed manually.

It'd be nice if the issue you linked to didn't occur (I guess by removing old kernels), but it seems to be something that mostly advanced users would come across -- or I guess they are people that think they are advanced (since they are playing with customizing the install).