For sure, the marketing team are taking advantage of the current generative AI trend.
But Grammarly has, for a long time, considered itself an AI product, even before it was cool. This, from a 2020 blog post on grammarly.com: "When you write with Grammarly, our AI analyzes each sentence and looks for ways to improve it, whether it’s correcting a verb tense, suggesting a stronger synonym, or offering a clearer sentence structure."
Before "AI" became tarnished by the LLM association, using it as a writer didn't seem to be as big an issue. Or an issue at all.
By showing the examples in my article, I demonstrated how using AI doesn't mean producing raw thoughtless content from an LLM. It can mean using AI tools to help craft and polish a piece, just like using Grammarly does.