Thanks for a great comment! I had a sense something like this may be true, but never looked up the research.
On your second point, we have evidence that LLMs can think without speaking, i.e., they can do planning or reflection in the forward pass, and that’s current models and LLMs. It’s possible that in the future that will be even more common.
I agree, but posts by @Jan_Kulveit for example (despite being cyborg written) have ~always given me great value, and I do not notice newer ones giving me less value—I do notice them being more frequent and equally useful, despite LLM smell being present in some sentences. So writing like that is an example where it is actually a net positive and would be hard (or somewhat unfair!) to label everything in a box as heavily LLM made and ignore it.