More a question. Is the option raw.lxc going to change to the option incus.raw ?
No, raw.lxc stands for raw options for liblxc. Incus also uses liblxc.
The fact that the LXD command line tool is called lxc was just a very annoying and bad management decision back in the LXD days which has caused no end of confusion for our users 
So to clarify:
- Linux Containers => Umbrella project for all things LXC, LXCFS, Incus, … (but no longer LXD)
- LXC => Low level container manager and library (interaction with the Linux kernel)
- LXCFS => Virtual filesystem to expose resource limits to LXC containers
- Incus => High level container and virtual machine manager, uses LXC for containers and QEMU for virtual machines