While DoD declared TCP/IP the future standard for military networking in 1982, IBM, DEC, and AT&T only adopted TCP/IP in 1984, a couple of months before Neuromancer went on sale. Gibson notoriously wrote it on a manual typewriter circa 1982-83. (It took a year from acceptance to put a novel manuscript into production back then: very often, it still does.)
ARPAnet existed in 1982, Public BBSs had been a thing for a while. But the publicly accessible global information network with visual representations of corporate presence? That was all in his imagination.
