Well the mountain trains drop anyone thats not having a good day, and leaves the strongest to fight at the top. Typically the strongest has been Froome, Geraint Thomas etc.
Dislodging Pogacar might already be seen as unlikely, so dropping Ben O'Connor, Martin etc helps Carapaz's position.
Given the way Ineos are doing such a sterling job of riding for Pogačar I'm not sure he needs any team mates.