That wasn't the question. The question would be whether a team would trade mass for drag and the answer is clearly yes. Every elite team has lighter and heavier bikes that are suited to different events.

from GP:

> Team Sky said that during a time trial stage bikes might be heavier to allow for better aerodynamic performance

(emphasis mine)

TDF time trials are almost never uphill. And yes, they have different bikes, showing that that while they might trade mass for drag during a time trial stage, they would do the opposite for hill climb stages. So "aero is the only thing that matters" is clearly false.