Well, APT rules will form part of the SCR rules even if SCR is scrapped so maybe they waited for clarity on the APT case before changing. Not like the PL to wait for confirmation of legality before doing anything though.
What gets me, is that the PL (apparently) say they are coming in line with UEFA rules by doing this. But, unless I am very wrong, and I may be, UEFA rules still include a PSR component that clubs in European competitions will have to meet, so I have no idea what they are talking about / doing .....