Someone is trying to get attention by saying things that appear to be obvious. I don’t think the “Iranian Sleeper Cells” are planning or plotting anything specifically for the World Cup. They would be smarter not to wait and just go blow themselves up at a minor league baseball game. The effect would be the same. The Iranians also don’t have a bunch of spare terrorists just lying around. They need their operatives to keep order in their own country. Not to mention that a lot of their agents are probably reluctant to give up their Door Dash and Uber gigs just to go blow themselves up.
They would be smarter yet if they just put out television commercials that showed the steady increase in gas prices over the past few months; they would get their point across, and nobody would be hurt.