Paying salaries isn't a question of winning or losing, paying salaries is a question of playing or not playing a competitive game. Since we have the playoff transfer deadline in place, you'll have to pay at least one week of salaries if you're in the playoffs.
So I don't really see where your strategy fits in. If you managed to sell your roster before mondays' update in the current system after losing tuesdays playoffs match you would have achieved the same. It seems to me only in the rare occasion you buy a monster team, pay their salaries at monday, win tuesdays game, accidently lose saturdays game - not relegation but only in conference finals -, you will save one week of salary in the new system. I'm not sure that would be such a massive disadvantage compared to the old system.