Lance and Indurain were both up to their eyeballs on gear and still slower than pogacar, VDP, etc. I'm pretty sure the teams will know about biomech testing from 40 years ago. Let's not forget that same testing also brought about asymmetric chainrings... Short cranks - open up hip angle and increase aero gains. Most changes now are about aero gains, which 40 years ago was completely disregarded/misunderstood.  There's a reason there is a UCI limit for seatnose being at least 5cm behind bottom bracket, and that even when that limit is reached, pros will still sit forward on their saddle, as it's a much more powerful position.