Yes, I had a related experience of reading a book and observing what I thought were claude-isms, only to realize it was written in 2019. Some of the common tells are actually good writing practices, but I guess they are best in smaller doses.
This is exactly why humans invented the idea of things going in and out of style.
Actually, AI was learning these 'AI-isms' even back in 2017/2018 (probably even earlier). I think a lot of people who just jumped on the imaginary AI bandwagon more recently don't realise the mannerisms AIs are adopting are not really new. At some point the bleed between 'you' or 'you' and AI will just become so transparent it will be obliterated, more likely than not.
Sure, that's where the AI got them: the training data. These phrases and cliches were very prevalent especially in corporate "white papers" and memos and marketing materials. There was a time when "stove pipe" was a common one too, along with "silo."
But the LLMs really seem to fixate on using the same ones in the same places all the time. I guess that's because that's the highest probability construction.