If firms and workers expect the prices to rise, the short run aggregate supply will shift to the left to SRAS2. (https://www.albert.io/blog/what-shifts-aggregate-demand-and-supply-ap-macroeconomics-review/)
In other words, the SRAS will DECREASE. But why? Especially considering that firms react with increased output supplied to inflation in the short run. According to theory of sticky prices such reaction happens because many firms with flexible output prices see increased inflation as chance to rip additional profit in the short run. So why would they decrease quantity supplied at all possible price levels (i.e. shift SRAS to the left) when they expect inflation to increase?