The rules say nothing about winning a "series".
They only refer to winning 2 games within a given period (Monday thru Thrusday) and (Friday thru Sunday). See copied rules below.
I anticipate if there is a rainout, those that selected the Phillies will be out but if they play, the game counts toward the 2 wins, if Phillies win.
Each week prior to the final week of the season is broken up into two rounds running Monday to Thursday and Friday to Sunday. You pick one team for that round and if it wins 2 games over the period, you advance to the next round.