I only stay on this particular variant of one of the 5 site designs every LLM spits out for long enough to check that - yes - it has the annoying thing where content fades in as you scroll, before closing the tab.

They got that from humans who made websites.

Ergo, the existence of the effect is not an effective filter for determining use of an LLM in the creation of the website.

if you like wheat, check out farmer & orchard (both are really cool)