That's not necessarily true. Iowa will never be the tipping point state. If Iowa indeed goes to Harris, then that most likely means states like PA, WI, MI, and potentially NC go to Harris too. In that case it doesn't really matter.If Iowa were that close both candidates would be there drumming up support.
Like I said, polls are just polls. But this pollster really knows how to poll Iowa and has been incredibly accurate in the past. Her 2020 polls did the same thing as this one, just in reverse. They showed Biden up until the very last poll three days before the election had Trump up by 7 or 8. She was dismissed at the time and everyone said the poll was dead wrong. She was right.