The temporary reduction of the Tuesday SQ38/37 turn may have more to do with one aircraft being out for reconfiguration, plus the maintenance schedule for the remaining four. They dropped Tuesday for a while earlier this year.....now, it's been back to daily, and sho' nuff, some horrendous delays due to waiting on an aircraft.
Once the whole group of five is re-done, the LAX schedule goes back to daily, and stays that way (well, at least for now).