Sorry, don't believe that for a second. They effectively gave Jumbo a break, let Rog sit in and encouraged Astana to think they could shut the gap even more. They want to secure Valverde on the podium and don't care about Nairo. That's fine, it's their choice, but that's what this is.
And I don't believe that for a second!
There were 3-4 Jumbo's, 3-4 UAE and 5 Astana's in the main group, that's some serious firepower. Movistar ripped that chase apart, except for Astana. Now if Astana wanted to race against Roglic, he would be doomed, between Movi and them. Someone would broke free, either Lopez or Valverde, or maybe even both.
And Quintana will gain this way maybe even more...