Not sure about that part... I thimk that Audi isn't in position to make such big desicions like "giving" orn "not giving" something witin VAG AG...
The 2.5T is an RS/Audi engine and I haven't seen any other RS engines in a VW before. Audi has had its 2.0T with Valvelift for quite some years already but the GTI is just getting it now.