It positioned from Ramstein, so it was always going to approach from the east, but it doesn't look like it was established for 25 (which has implications for CDG traffic) at any stage.
I don't understand your comment about CDG. All landings on 25 at LBG (which tends to be the predominant runway in use) pass just to the south of CDG. It would make perfect sense that they made a standard approach to 25 up to a point and then broke off for 21. They may have first edged right before staring the left turn. Of course you may have seen otherwise on some tracking app, but you haven't said so.