You're correct they do polarized training, but the overall times have gone done significantly. This is due to polarized training, i.e. yes when they train long and easy athletes go long and easy, however if there is high intensity training you do relatively short sessions but full on. Importantly the middle ground sessions, where people trained for hours with medium intensity have completely disappeared. Read any interview with an older professional cyclist who experienced the transition, they all mention that they are training significantly less time now.