BENGALURU—The U.S. economic rebound has been dented in Q3, partly on the spread of the Delta coronavirus variant, with economists in a Reuters poll also pushing their expectations back to November for when the Federal Reserve announces an impending policy shift. Like in most countries, the U.S. economy is facing global supply chain disruptions due to the pandemic, which has also pushed up inflation. The shift in expectations over the past month for when the Fed will announce a taper to its $120 billion in monthly bond purchases has been almost as sudden as the unexpected dent to the recovery in the current quarter. For now, most economists say the growth slowdown will be temporary, and so far have not made any major changes to a strong outlook for next year. Despite President Joe Biden’s mandates to spur Americans who are not vaccinated to get a shot, children heading back …