Linux isn't POSIX compliant, and as far as I know has no plans to ban newlines in filenames, or even add an option to disable newlines.

In past, there have been Linux-based operating systems that have been certified as Single Unix Specification compliant, and part of said specification is POSIX. I would imagine GNU and Busybox and Musl will be willing to implement the changes proposed by POSIX 2024, which inevitably leads down the road of newlines being banned.

I know Linux allows newlines in filenames, but every time I hear it I want to drink.