Byte Magazine had a history of forward-looking articles for microprocessor and software technology. There were entire issues devoted to LISP in (1979), Smalltalk (1981), and the 68000 (1986). It wasn't that C was new, it wasn't, but in 1984 it was certainly new to their target audience, which was the micro-computer industry.
While it's true that C compilers were available for MS-DOS and CP/M in '84, these were by no means mainstream, and were prohibitively expensive. Turbo Pascal was still taking the world by storm, and it would be another three years before Borland would introduce an 'ANSI Compatible' C compiler and IDE - the much anticipated (by me anyway) Turbo C in 1987.
While it's true that C compilers were available for MS-DOS and CP/M in '84, these were by no means mainstream, and were prohibitively expensive. Turbo Pascal was still taking the world by storm, and it would be another three years before Borland would introduce an 'ANSI Compatible' C compiler and IDE - the much anticipated (by me anyway) Turbo C in 1987.