The tender is not for aerodynamic WAP5 locos. It is for twin Bo-Bo locos (like the WAG12) suitable for 200kmph.
We don't really have any aerodynamic locos in IR. The loco that is being publicized as 'aerodynamic WAP5' is also not really a suitable high-speed loco. Other than a slightly more pointy cab face, there really aren't any high-speed suitable features in that loco.
At the speeds we have in IR, many other aspects of the loco, like the gap between the loco and the tracks, the way the equipment on the...
more... top of the loco (panto, insulators etc) protrude above the loco etc., are also equally important things for aerodynamics. None of these have been changed in the aerodynamic WAP5 we have now. So, we are not losing much by not building more such locos.