It's hard to know. Maybe with some pitchers, it would work well, but others, used to the routines of every 5th day pitching, maybe not.
Starters do have a "throwing day" between starts, so maybe the adjustment might not be so unsettling.
Would throwing 3-4 innings every 3rd day vs 5-6 IP every 5th day be the trend of the future?
Over a 15 day/game period the 3rd day guy might pitch 17-18 innings (5 x 3.2 IP), while the every 5 day guy might pitch 17-18 IP (3 x 5.2), too.