alt Hacker NewsCheck out eg this paper about the OS: https://cseweb.ucsd.edu/~voelker/cse221/papers/qnx-paper92.p...
Yes it has some source-level Unix compatible app-facing interfaces, but we don't call the Steam OS/Deck a Windows-like either. (eg Windows NT was also POSIX certified)
I'd definitely call the Steam Deck unix-like, although GNU/Linux is less POSIX-conformant than QNX is.
Source-level and command-level compatibility is what makes something "unix-like". Paying a hefty annual license fee to the Open Group is what makes your OS "Unix". I don't believe there is any benefit to BlackBerry paying such a fee so they can slap their logo on their web site since the US DoD is not a target market for them.
Nevertheless, arguing that something is not "unix-like" just because it's very much like Unix is, well, odd.