I’ve no experience of this, I read the above as....
boxster “S” Rear will fit over 25mm disks
rears need not to be reversed - Rear right fits front right - the nipple will remain at the top to expel air in the system when you bleed them (using front callipers you’d need to swap left to right to have the nipple at the top? Ie reversed).
thats my take on what’s written in your quote, don’t shoot me if I’m wrong....