I have definitely noticed other people using LLM-choice words, myself included, more frequently. It's a strange phenomenon to witness. Obviously the models got them from us first so there must've been some popularity there prior, but the boost is clear. Blast radius, load-bearing, shape, and so on. Or maybe they were always there and my confirmation bias is in high gear.
One I've started noticing is the "quotation marks around a phrase awkwardly trying to bundle a concept" thing. Like all LLM cliches it's something that has been used in writing for a long time, but I've seen it so much more recently. I think lots of people have picked this up from seeing LLMs use it. But like you said, who knows.
I do have a sneaking suspicion it's a mix of things, I'm at the point now that I do get a bit of an odd feeling whenever I'm reading AI produced content
I suspect over time it will get good enough that I'll need a larger sample size to identify it, however that won't solve what I think of as the "why does this need to exist" problem, I've noticed that a fair bit of AI content hits that mark, it can be fun, but I've not experienced that feeling of engaging with something that's been well thought out / executed, maybe we'll hit that point[0], but I suspect it will take a while