Yeah so I had this discussion with some people who actually like ordinals and "inscription" was never a term before ordinals. The conversation was being had because of a coindesk article that referred to an op_retrun as an inscription.

We got a quote from this website https://docs.ordinals.com/inscriptions.html

"Inscriptions inscribe sats with arbitrary content, creating bitcoin-native digital artifacts, more commonly known as NFTs."

So if it doesn't create a token or something that can be traded, who's ownership can be transferred from person to person, then it is NOT an inscription. Therefore, Satoshi did not inscribe on-chain. He put arbitrary data on-chain, but to put arbitrary data on-chain does not seem to be the definition of what an inscription is.

Satoshi also mined that block himself, didn't burden others with it and he wasn't doing it with the aim of trading arbitrary metadata for Bitcoin, these inscriptoor arguments are so silly, it is all whatbaboutism and charactures of laissez-faire