Except the issue is that Git, which includes validation and history integrity, was invented in 2005 and predates the publication of the bitcoin whitepaper by 3 years.

The point being that all the hype about "blockchain everywhere" came about because of bitcoin. If people are now starting to refer to just the "hash of blocks with previous blocks" (i.e. the "Timestamp Server" section of the original bitcoin whitepaper) as blockchain withOUT the proof of work/stake part, well then you really are just rebranding old tech as blockchain, because it was the proof of work part that was really the new thing in bitcoin.