Like I said,... The issue is not in any way linked to it (region-restriction and sector-scrambling),...
If that happens, the DVD video becomes "region-free".
I've done that before, to get a region 5 disc to be played on one of the region 3-only DVD players I used to use.
Of course, something that will be very great is a piece of software that makes the PS2's DVD player region free.
I know that it's not a hardware limitation, as the first Playstation 2 was *region-free* when the user pressed a certain combination of buttons when using the DVD Player v1.00.