To me it looks like switch_to_fb= duplicates functionality from console=

If it is not specified, "the OS" should just use what the kernel thinks the
console is. In practice this is either the monitor. Or it can be a serial
device, like on non-x86 the kernel will reuse the firmware output device.

In case the admin wants to have a specific console, and the default does not
fit, the will documented console=tty1|ttyS0|ttyAMA0 option will deal with it.