Forgive me, but I think you misread my grandparent comment's intended meaning. The assertion was that TCP/IP was standardized in 1983, and this is, in fact, technically correct. The unwritten subtext was that TCP/IP was standardized as the protocol in use on ARPANET, with the cutover from NCP to be concluded on 1 January 1983.

"It is really very important for everyone to notice the deadline for completing the cutover to IP/TCP and the elimination of NCP from use in the ARPANET." https://groups.google.com/g/fa.tcp-ip/c/HDoq18adT2Y/m/HwoFGx...